Sciences Subject (BS11001)

101 Soil - It is a renewable resource which can decay easily. We should preserve the quality of the soil, keep it rich with nutrients as long as possible, and avoid using toxic chemical substances in cultivation. Water - It is a renewable resource because it will come back again in the form of rain. We should protect the quality of water resources so that we have good water to use at all times. Natural resources are necessary for human beings because they can be used and benefit human beings in many ways. Wasteful and unwise use of these resources will result in many problems. Generally, we can separate natural resources into different types as follows: Soil resource Soil comes from disintegrated and broken rocks mixed with various organic matters, including water and air. Soil can be classified into different kinds based on its composition. The kind of soil that can be found in Thailand varies according to the nature of its location. ๐ Floodplains along the rivers are composed of piled up sediments, mostly young sediments which the river has brought from different places. Soil commonly found on floodplains, such as banks of the river in Ayutthaya and Pathum Thani, is fine clay that becomes tightly packed when dried. ๐ Very low land is regularly inundated and thus accumulates many decomposed plants and animals which form into layers of soil with a high amount organic matters. Such areas can be found on the shore of Narathiwas Province and Bueng Boraped of Nakhon Sawan.

102 ๐ In the coastal areas, there are many beaches and sand dunes which are low in nutrients. Coastal areas line along the sea shores such as the coast of Prachuab Khir Khan. ๐ In areas further away from the river, soils are washed away by the flow of water and contain low nutrients. Soils commonly found in these areas are clay which continually decrease in richness and become an unproductive soil. ๐ In low mountain areas, soils are mostly covered with natural forest so they contains a lot of organic matters. However, if the forest is destroyed, the soil will be severely eroded by water and wind, causing rapid deterioration. ๐ Soils that contain a lot of alkaline substances, such as limestone and marl, are rich in nutrients which come from the decomposition of these substances. This type of soil is good for field crop cultivation. Making use of soil - Efficient and sustainable use soil include: ๐ Rotation crop cultivation

103 ๐ Terrace crop cultivation ๐ Forest grown in hilly areas which are not used for cultivation Soil resource problem - There are 2 kinds of soil problems in Thailand: natural problems and man-made problems. Natural problems Minerals in the soil being washed away Corrosion and erosion of soil Man-made problems Growing the Growing crops Deforestation Burning the same crop without nourishing for industrial forest repeatedly the soil use

104 Water resources One third of the Earth is made of water, a renewable resource that can recycle itself so the Earth will never run out of it. However, water can be degraded or become low in quality. There are 2 main sources of water: ๐ Surface water includes canals, rivers, streams, lakes, and reservoirs. The amount of water that these sources can produce depends on the following factors: - Amount of rainfall - Water loss rate from evaporation and transpiration - Water storage ability ๐ Subsurface water is the water located beneath the ground and is called ground water. Its amount depends on the following factors: - Amount of water coming from the surface - Ability to store the water between layers of rocks Importance of water – Water is important for living things in many aspects, including: ๐ Agriculture: for cultivation, animal farming, etc. ๐ Water transport system ๐ Industry ๐ Consumption Conservation of water resources can be done by the following methods: ๐ Development of water resources such as dredging shallow waterways ๐ Using water efficiently and not wasting water

105 ๐ Stop deforestation ๐ Prevent water resources from pollution Forest resources Forest is a very important part of the ecosystem. It is a source of water, provides habitats for wild animals, prevents soil erosion, and plays a significant part in the circulation of substances in nature, etc. Forest is essential for the Earth Forest conservation - Promote the understanding about the significance of forests to the lives of human beings, animals and plants on the Earth. - Promote forest conservation awareness of people in communities. One way to achieve this is through the legislation of Community Forest Management Act. - Enact laws to protect forest areas and issue regulations against deforestation. - Plant trees in the areas of degraded forest. This can be done in collaboration with community members on various occasions. - Keep abreast of news about the environment for the latest updates on forest and environment preservation initiatives. Mineral resources

106 Mineral resources mean all the minerals in the world which are found in the ground and under the water. Mineral resources have various use and benefits for human beings. Mineral source: Minerals have been naturally formed in the Earth crust by the following causes: - Natural phenomena such as volcanic eruptions and of tectonic plate movement that have caused minerals under the surface of the Earth to be pushed up. - Chemical transformation of different types of rocks on the surface of the Earth which have resulted in the formation of new kinds of minerals. Thailand is rich in minerals and its mineral sources are in different regions such as: - Lignite: Commonly found in Pudam District of Krabi Province, Mae-Moh District of Lampang Province, and Lee District of Lampoon Province. - Oil shale: Found mostly in Mae-Sod District of Tak Province. - Potash salt rock: Found across the northeastern region of Thailand. - Gemstone: Found mostly in the eastern region and the western region of Thailand. - Tin: Found mostly in Pang-nga Province and many southern provinces of Thailand. Mineral conservation Minerals are non-renewable natural resources. So, the preservation of minerals is very important and requires cooperation from everyone. There are many ways to preserve minerals as follows: - Use tools and equipment wisely, maximizing the benefits from them. - Use minerals that suit the needs and their properties. - Sort out garbage according to its type, such as recyclable matter like food scraps, recyclable materials like glass bottles and tin cans, and toxic materials like different kinds of batteries and electronics circuit boards. This will help facilitate the recycle process and reduce the use of minerals. Impact of local natural resources consumption Everyone must have heard the news about the degradation of the environment. However, if we ignore this issue and do not realize that our environment is in danger, it will be too late to change it back to the condition that enables lives to exist. If this actually happens, human beings inevitably be faced with unexpected consequences because we

107 are a part of the environment. Human beings should be aware of current environmental problems and try to find solutions seriously based on the correct understanding. Natural resources preservation is not too difficult to do. All that we need is just to be determined and committed to adopting environmentally-friendly behaviors. With this, natural resources and the beauty of our environment will stay with us for a long time. Guidelines for preservation of natural resources and the environment are as follows: - Begin with simple things nearest to us such as protecting the environment near your home, village, or district. - Seek more knowledge about the characteristics of the environment surrounding us because each location has its own distinct environmental conditions. - Proceed with environment preservation initiatives step by step ad try to gain support from other people who share the same idea to create a synergy of workforce and ideas. Conserving natural resources and the environment can never be too difficult if we really want to do it. Re-using a plastic bag is already an act of reducing waste. Sorting out garbage is another meaningful contribution to natural resources preservation. These examples are only a small part of the ways to protect our environment. With cooperation from everyone, we will have a good environment to live in and sufficient natural resources for consumption. Principles of natural resources conservation For optimum effectiveness, methods of natural resources conservation and management should be based on these principles: 1. In the preservation and management of a natural resource, impact on all types of natural resources should be taken into account as natural resources are interrelated and interdependent. 2. For effectiveness, natural resources management planning should be harmoniously connected with the development of society, economy, politics, and quality of life and contribute to the equilibrium of the ecosystem. 3. Environment conservation requires cooperation from all parties which include residents in big cities and remote areas as well as those who govern the country. Constant awareness of the significance of natural resources and the environment is very important.

108 Conservation efforts should begin at the individual level and then expand to the community level, the national level and the global level. 4. The success in the development of a country depends on the richness and security of its natural resources. Therefore, destroying natural resources is like destroying the wealth and the future of our country. 5. Powerful countries that are highly industrialized need a very large amount of natural resources for their industrial sector. Therefore, developing countries should protect themselves from being exploited by powerful countries. 6. Technologies can be useful for natural resources management. However, it is important to recognize that the goal of management is not only for the physical well-being of people but also for their psychological well-being. 7. Using local natural resources must be based on correct knowledge about conservation in order to bring sustainable benefits to human beings in every aspect. Also, advantages and disadvantages as well as waste related to the use of natural resources should be considered. 8. Rare and essential natural resources must be thoughtfully protected. We must also try to increase them physically and economically as best as we can. We should also keep in mind that overconsumption of natural resources puts the environment in danger. 9. Renewable resources should be conserved by at least maintaining the balance between the rate of reproduction and the rate of consumption or between the rate of death and the rate of birth. 10. Try to improve and find innovative ways for effective use of natural resources. Do research to find new substitutes. 11. Educate the people, help them to understand the importance of natural resources conservation. Siriprot Pholsit (1988 : 196-197) suggested the following methods of natural resources protection: 1. Preservation - Maintaining quality and quantity of natural resources by using them efficiently such as catching only fully-grown fish, not ones that are too small in order to allow them to grow as replacement of the fish caught for food.

109 2. Restoration - Restore damaged natural resources so that they can return to the original condition or at least close to that. Sometimes, this is called development. Examples include a forest restoration or growing trees after a forest has been completely destroyed to restore the environment of the area and make the area a forest again. 3. Development and efficient use ‟ For example, squandering metallic minerals before using them in the manufacturing of machines, engines, or other equipment which are more useful. 4. Re-use or recycle – For example, steel scraps can be re-melted and re-used. 5. Replacement/substitution - Using other kinds of resources which are more abundant to replace rare or scarce natural resources such as replacing iron with plastic in some parts of a machine or vehicle. 6. Exploring and discovering more sources of natural resources - This is to prepare for future use. For example, the exploration of petroleum sources in the Gulf of Thailand led to the discovery of natural gas which can be used for short-term and long-term consumption as well as reduce the amount of natural gas imported. 7. Inventing artificial objects - This is to avoid or reduce the consumption of natural resources that are conventionally used. Examples of artificial materials include synthetic rubber, artificial clothes and artificial silk. 8. Spreading the knowledge and understanding about natural resources and environment conservation – This is to gain full cooperation from all parties. The government should play an important role in the conservation of natural resources and the environment by planning the management carefully. 9. Founding associations – Set up associations or clubs that promote the protection of natural resources and the environment.

110 Topic 2: Environment Meaning of environment There are concrete environment (physical things, capable of being perceived by senses) and abstract environment (such as culture, norms, traditions, beliefs, etc.) They are interrelated and inevitably affect each other. Environment includes everything that is surrounding us, both living and non-living things, and has the characteristics of a cycle. Every element in a cycle is interrelated and affects the whole system. Environment can be separated into 2 main types: 1. Natural environment such as forest, mountain, soil, water, air, and other resources 2. Man-made environment such as urban communities, buildings, archeological sites, and artifacts. Causes of environmental problems There are 2 main causes of environmental problems: 1. Population growth - The world’s population growth is still considered an exponential growth. An increase in the number of population implies more needs for natural resources consumption, including food, shelters, and energy. 2. Economic growth and technological development - Economic growth is accompanied by higher standard of living which results in the consumption of natural resources in a manner that is beyond the basic needs of life. It also leads to higher rates of energy consumption and demand. With advanced technologies, people can use natural resources more conveniently and at a higher rate of consumption. Consequences of environmental problems Consequences of environmental problems are a decrease in available and usable natural resources caused by careless and wasteful use of national resources. For example, forests are destroyed; soil becomes unproductive; water becomes scarce, and there is more pollution in water, air, sound, food, chemicals, which are caused by accelerated industrial development.

111 Natural changes of local environment include flood disasters such as flash flood which can destroy crops and plants that cannot survive in inundated areas. Floods also cause damages to other living things, especially human beings and animals. Storms are also a cause of environmental changes. They can cause trees to fall because of the strong winds, causing damages and changes to the environment. Volcanic eruption is another cause of environmental changes. The heat of lava flowing from the crater destroys living things and the gases coming out of volcanoes affect the condition of the weather. Man-made changes in local environment include the loss of trees on mountains that become bald because of deforestation, the loss of wildlife habitat and food, the lack of water, pollution in water, air, and soil such as soil contamination and soil degradation. Global warming Global warming or climate change is a major problem at present is indicated by the world temperature which is increasing continuously. This problem is mainly caused by greenhouse gases. The greenhouse effect has a significant effect on the world. Gases like carbon dioxide and methane retain some amount of heat and prevent the heat from returning to the atmosphere. Without this effect, the world’s climate conditions would be like those of the Moon where the weather is extremely cold at night (and extremely hot in the day time because there is no atmosphere to filter the energy from the Sun). As this process is the same as the principle of greenhouses used in growing plants, it is called the “greenhouse effect.” However, continuous increase of CO2 released by manufacturing factories, automobiles or any activities which involve burning of fossil fuels (such as coals, oil, natural gas, or hydrocarbon compound) causes the CO2 to exceed 300 ppm (300 part per million) for the first time in 600,000 years. This increase of CO2 leads to more retention of heat on the Earth and causes global warming as we see today. The record of global warming in the period of 10 years, from 1990 onwards, shows that the Earth experienced record-high temperatures in 1990, 1995, and 1997. Although the

112 prediction of climate change is still uncertain in several aspect, but the question that people are disputing has changed from “Is the world is really warmer?” to “What are severe and continuous effects of global warming on living things on Earth?” Therefore, the longer we delay the act to resolve this problem, the more that we, particularly our descendants, will be affected by it. Cause Global warming is a looming disaster. We all know very well that it is caused by human acts which include burning of fossil fuels such as coal, oil, and natural gas to produce energy. We are also well aware of its effect on the Earth such as the melting of the polar ice, the rising of the sea level, severe droughts, spreading of serious epidemics, floods, coral bleaching, and sudden occurrence of severe storms. Regions most severely affected are coastal countries, island countries, and the developing region of Southeast Asia. The Intergovernmental Panel on Climate Change, which is a scientific body operating under the collaboration between scientific organizations and the United Nation, has been monitoring the effects of global warming and found a new substantial evidence which proves that human beings are the main cause of the rising world temperature during the past 50 years. We have caused the temperature everywhere on earth to rise about 1.4- 5.8 Celsius degrees. Climate change is not a gradual, but a sudden change. It seems to grow more severely as time passes by. Some obvious examples are severe droughts, storms, floods, rainstorms, tornadoes, landslides, and sudden appearance of storms. People who live in the area directly affected by these disasters have not received proper assistance and care. It is expected that the rising Earth temperature will cause a drop in the quantity of food available which would lead to about 60-350 people around the world living in famine and starvation. In Thailand and the Philippines, there are many energy projects which evidently affect the ecosystem. Relevant consequences include anomalies in seasonal rainfall and change in the amount of rainfall, forest invasion and deforestation, rising sea level and sea water temperature which have strong effects on the ecosystem in coastal areas. The rising temperature of the sea water affects the sea surface colors. As a result, coral reeves are affected and damaged as well.

113 Thailand is an example of a coastal country and the length of its coast is about 2,490 kilometers. This is very important to the economy of the country, especially fishery and aquaculture industry. The recent instability of the weather affects agriculture in Thailand. It is predicted that if the sea level rises 1 meter by the next decade, Thailand will have less beaches and coastal areas. In such case, seaside resorts and the tourism industry in many popular tourist attractions such as Pattaya and Rayong will be directly affected. Bangkok cannot avoid the impact from the rising of the sea level either. Climate change also has strong effects on health problems. Higher temperature and humidity can lead to more mosquitoes that spread malaria and exanthematous fever. Furthermore, diseases that can be communicated through water such as cholera are likely to increase rapidly and continuously due to the higher temperature and humidity of the region and inefficient healthcare education. Poor people are likely to be most severely affected. Today, the initial signals of the climate change are clearly seen. Thus, we should consider whether it is worthwhile to wait until more data are discovered or more knowledge are found before doing something about it for it is possible that it might be too late to solve the problem by that time. Effect of global warming Although the temperature of the Earth has risen only a few degrees, the change has caused a domino effect and will eventually affect the Earth. Such effects are already obvious in many countries, including Thailand. One of the examples is the melting of ice around the world such as in glaciers, polar ice, and Greenland ice sheet which is one of the largest ice sheets on the Earth. The melting ice increases the level of water in the ocean. The higher temperature makes water molecules expand and that doubles the increase of water in the ocean. Many major cities along the coast are now lower than the sea level. It is predicted that when the ice is completely melted, the sea level will rise 6-8 meters. Another evident effect is the occurrence of cyclones which are more frequent and severe. According to news reports, there have been many hurricanes hitting the United States of America in the past few years and each one of them was of disastrous magnitude.

114 This phenomenon can be explained by the principle of energy that when the ocean is warmer, storms receive higher energy and become stronger. In addition, global warming also has also caused the worst drought in the Earth’s history. Today, global warming becomes even more intense because so many trees in the forest are dropping dead because of drought. Dead trees cannot absorb carbon dioxide but they produce gas during the process of decomposition. There are many alarming signs from other natural disasters which are the results of global warming. How to solve the global warming problem How can we stop global warming? It is troubling that we may not be able to stop the looming global warming disaster although we totally stop producing greenhouse gases today. The Earth is like a machine with many small sets of mechanism that work together at the same time. To make it respond to any stimulation and to make everything return to the right balance, it will take a very long time. In addition, the new balance will be much different from the present condition anyway. However, we can still reduce the effects of global warming in the future to a manageable level and slow down the global warming process by reducing the production of greenhouse gases. Since the gases come from the energy consumption, saving energy is definitely a way to slow down global warming.

115 Activity 1 1. Give an example of human actions that may cause changes to the environment. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… 2. Give 2 examples of how human beings can be affected when the environment is destroyed. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… 3. The first kind of energy that gave birth to living things on Earth was..................... 4. In the past 30 years, forest resources in Thailand have decreased significantly. Explain how this can affect us. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… 5. The major cause of natural disasters that human beings are facing today is … ……………………………………………………………………………………………… ……………………………………………………………………………………………… ………………………………………………………………………………………………

116 6. The Earth’s largest source of energy is ....................................................................... 7. What is the type of crises caused by wasteful use of resources by human beings?....................................................................................................................................... 8. To maintain the balance of nature for future generations, how should we adjust our use of natural resources? ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… 9. What should human beings do to build a balance that would enable human beings and the nature to live together and depend on each other effectively? ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… Activity 2 Separate learners into groups. Each group is assigned to study about an environmental problem as well as solutions to the said problem. Then, present to the class to exchange information. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ………………………………………………………………………………………………

117 Lesson 6 Natural Phenomena Main learning essence The chapter covers the natural phenomena related to daily life, the occurrences of cloud, fog, dew, rain, hailstone, and the local weather for well-being living. Expected learning outcome 1. Be able to explain the occurrences of cloud, fog, dew, rain, and hail. 2. Be able to describe the local weather Content scope Topic 1 Occurrence of natural phenomena Topic 2 Local weather forecast

118 Topic 1 Occurrence of natural phenomena 1.1 Cloud “Cloud” consists of water vapors floating in the air which, while being heated by the sun, rise higher to collide with the cold air mass above and condenses into small droplets. Those droplets combine into a cloud. The obvious example of the occurrence of cloud is “contrail” which is a man-made cloud. When a jet plane flies at the height above the condensation level, water vapors in the hot air spewed out of the engine collide with the cold air and condense into droplets. Due to the aggregation with the soot from the engine as a condensation core, we then see a white-cloud smoke spewed out of the end of the engine as a long trail. Similar to artificial rain making where a plane sprays the chemical “silver iodide” to be a condensation core for water vapors in the air to adhere and condense into clouds. Cloud nomenclature Natural clouds appear in two shapes, i.e. chunk cloud and sheet-like cloud. We call a chunk cloud “cumulus” and call a sheet-like cloud “stratus”. If chunk clouds are floating together, we combine the two names and call them “stratocumulus”. In the case of a rain cloud, we add a word “nimbo” or “nimbus” which means “rain” into the name. For example, we call a chunk rain cloud “cumulonimbus” and call a sheet-like rain cloud “nimbostratus”. We divide clouds according to the altitude into 3 levels as low- level clouds, medium-level clouds and high-level clouds. For a medium-level cloud (at the altitude of 2 - 6 km), we will add a prefix “alto”, which means “medium altitude”, for examples, we call a medium-level chunk cloud “altocumulus” and call a medium- level sheet-like cloud “altostratus”. For a high-level cloud (at the altitude above 6 km), we will add a prefix “cirro”, which means “high altitude”. For example, we call a high-level chunk cloud “cirrocumulus”, call a high-level sheet-like cloud “cirrostratus” and call a high-level cloud which looks like a feather “cirrus”. Cirrus Cirrocumulu Cisrro Cirrocumulus Cirrostratus (high level) Altostratus Alto Altocumulus (medium level) Nimbostratus, Stratus Strato (low level) Cumulus, Cumulonimbus (rain cloud) Sheet-like cloud Stratocumulus Chunk cloud (rain cloud) A diagram for cloud nomenclature

119 Categories of cloud Meteorologists divide those ten types of clouds into 4 categories as follows: 1. High-level clouds are clouds which form at the altitude above 6 km. Clouds at this level often consist of small pieces and are almost transparent. They can be divided into 3 typesas follows: Cirrocumulus: white clouds, ice crystals, small wavy stripes, cover a large area of sky Cirrostratus: similar to cirrus but they spread out into a thin sheet in the direction of the wind, thin sheets, white, ice crystals, cover a large area of sky, translucent to sunlight, sometimes refract light causing solar corona and lunar corona Cirrus: striped clouds, white, feather-like, ice crystals, usually occur in a good-weather day with a dark-blue sky 2. Medium-level clouds are clouds which form from water droplets or ice crystals at the altitude of 2 ‟ 6 km. They can be classified by the shape as follows. Altocumulus: chunk clouds, white, appear as a group of small pieces similar to a flock of sheep, with small gaps between clouds, sometimes form at a lower altitude and become similar to stratocumulus or occur in chunks stacked up like the top of a castle Altostratus: sheet-like, cover a large area of sky, usually grayish because they block the sunlight or moonlight making them look hazy, may cause a sprinkle of rain

120 3. Low-level clouds are clouds which form at the altitude of less than 2 km from the ground. They can be classified by the shape as follows. Stratus: thin sheets, white, cover a large area of sky, may cause a sprinkle of rain, usually occur in the morning or after raining, sometimes float just above the ground and are called “fog” Stratocumulus: chunk clouds floating together with each other, do not have a definite shape, have only small gaps among them, usually occur when the weather is not good, grayish because they float in the shadow of the clouds above Nimbostratus: dark gray thick-sheet clouds similar to wet ground, cause light rain or a sun shower without thunderstorm or lightning, usually make the rain visible as falling from the cloud base 4. Vertical clouds are clouds at 500 - 20,000 m from the ground. They are divided into 2 types as follows: Cumulus: fluffy white clouds, cauliflower-like, the cloud base is gray since it is sufficiently thick to block the sunlight causing shadows, usually appear in a good-weather day with a dark blue sky Cumulonimbus: vertically-formed clouds, developed from cumulus, very large, covering the entire province, cause other natural phenomena such as lightning, thunder, thunderstorm and sometimes hail

121 Color of clouds The color of a cloud indicates the phenomenon which occurs inside that cloud. Since a cloud is formed by water vapors rising to a higher altitude, being cooled down and condensing into small droplets, these droplets are of such a high density that the sunlight cannot shine through, causing a reflection of sunlight. We can thus see a white cloud. As the cloud condenses further, the water droplets combine to become larger until finally fall down as rain. During the process when those water droplets become larger, the gaps between droplets also become larger, and they allow more light to go through. If that cloud is sufficiently large and gaps between droplets are sufficiently wide, the incoming light will be absorbed in the cloud and only a little portion will be reflected back. This absorption and reflection of light cause us to see a cloud from white, gray to black. The color of a cloud can be used to describe the weather condition. - Light green cloud is caused by the scatter of sunlight from ice. Green cumulonimbus indicates the formation of rainstorm, hailstorm, violent storm or tornado. - Yellow cloud is rarely seen, but it can occur from around the end of spring to the beginning of fall which is the period of wildfire. The yellow color is caused by dust and smoke in the air. - Red, orange or pink cloud normally occurs during sunrise and sunset. The color is caused by the scatter of light in the atmosphere, not by the cloud directly. The cloud is just a reflector. But in the case of huge rainstorm at the same time, the color of the cloud will be crimson like blood. 1.2 Fog Fog results from the condensation of water vapor in the air. When in contact with cold air, it condenses into water droplets looking like white smoke floating on the ground. Sometimes, it can be so thick that it hinders transportation. On a humid day and a clear sky, when night falls the ground cools down rapidly and the water vapor in the air above the ground condenses into water droplets. The fog caused by this process has a low temperature and a high density. The fog moves downwards, and can be densely found in valleys. When the weather is warm with high humidity and the air collides with a cold surface such as the water surface of a lake, the air will condense into water droplets in the same way as the droplets around the glass of iced water.

122 Figure 2 Appearance of fog 1.3 Dew Dew is a form of droplets clinging on the ground or trees formed by condensation of water vapor on the surface of objects. It radiates the heat out until its temperature is lower than the dew point of the surrounding. Since each surface has a different heat radiation, the amount of dew that covers each type of surface will be different. For example, early in the evening, there may be dew covering grass but no dew covering the concrete floor. Another reason that dew usually forms on leaves is that the leaves of plants have transpiration which fills the surrounding with high humidity. Figure 3 Appearance of dew

123 1.4 Rain Rain is water vapor which condenses into water droplets and falls from the cloud onto the Earth surface. Rain is a kind of precitipitation. Other kinds of precipitation, apart from rain, are snow, sleet, hail and dew. Rain can be classified into 4 groups based on the causes of rain as follows: 1. Convective rain: It is caused by convection which leads to the upward movement of warm air. 2. Orographic rain: This type of rain occurs when air masses carrying humidity from the sea clash with mountains. This causes the air to rise. 3. Cyclonic rain: When high pressure air passes a low pressure area, air masses in the low pressure area rise. 4. Frontal rain: When warm air masses clash with cool air masses, warm air masses rise. 1.5 Hail Hail is a form of solid precipitation occurring when water droplets solidify and turn into ice pellets. It occurs when warm air masses rise and bring with them rain droplets which clash with cool air masses on higher air layers and then condense into ice pellets. Afterwards, the ice pellets fall down to warmer air layers and accumulate more humidity. This adds more layers to the ice pellets. Due to the wind, this process can repeat itself several times until the ice pellets become too heavy for the wind to carry and then they fall down on the earth surface. Generally, hail occurs in areas under the influence of high heat during the transition from summer to rainy season. Hailstones are commonly 2-3 millimeters in diameter and can cause damage to animal farms, plantation, homes and airplanes. Figure 4 Appearance of hail

124 1.6 Case study: cause and effect of frost Frost occurs when the temperature of air vapor near the ground reaches the dew point and condenses into water droplets. If the temperature continues to decrease and falls below the freezing point, the dew will solidify and turn into frost hanging on leaves and grass. Frost is quite rare and is found only when the weather is so cold that dews on grass or twigs become solid at zero Celcius temperature or slightly below. Effect of frost Frost has both advantages and disadvantages. While frost is an interesting phenomenon for many people and helps promote tourism, it also has negative effects on agriculture and can damage crops and plants. Frost can cause, for example, rice in heading stage to produce low quality grains, crops to be in dormancy, vegetable leaves to become distorted and brown, and leaves of banana trees, coconut trees and durian trees to wilt and fall. Prolonged duration of frost will certainly cause trouble to farmers.

125 Topic 2 Local weather forecast Weather forecast means the prediction of future weather conditions and natural phenomena such as the prediction of tomorrow’s weather conditions. To forecast weather, the following 3 factors are required: 1. Knowledge and understanding of phenomena and atmospheric processes which are acquired through observation and data collection. Humans have learned to observe the weather since a long time ago because human lives are inevitably affected by the weather. Because of this, knowledge about beneficial and dangerous weather conditions is vital for human lives. Weather observation gives us information about the causes of different weather conditions. 2. Current weather conditions are important for weather forecasting. Weather surveillance through both surface observation and upper air observation can provide information about temperature, atmospheric pressure, humidity, wind and cloud which is fundamental to weather forcast. 2.1 Air temperature means the the level of heat in the air which affects air circulation. Air masses flow from cooler areas to warmer areas. Generally, air temperature in different areas varies and is constantly changeable. Air above the ground is commonly warm and dry while air above water surface is cool and humid. Thermometer is a device for measuring temperature. There are 2 kinds of temperature measurement units: degree Celcuis and degree Fahrenheit. Modern inventions which help improve the precision of weather forecast include a radar weather surveillance and a meteorological satellite. 2.2 Atmospheric pressure is the force of air exerted on the surface and can be measured by a tool called “barometer.” The measurement units are millibar and pound per square inch. Atmospheric pressure can be divided into 2 types: Low pressure area or low pressure refers to an area with low air masses. As the weight of air above the surface is low, the air rises and is replaced by heavier air. This process causes wind. High pressure area or high pressure refers to an area where atmospheric pressure is higher than its surroundings. It is also known as anticyclone and occurs when the air deflects from the high pressure center and is replaced by air on the upper layers. As this process causes only a rise in temperature but not vapor condensation, the weather and the sky are clear.

126 2.3 Wind is a flow of air. Strong wind signifies rapid movement of huge air masses. In wind observation, it is important to know about both the wind direction and the wind speed. Weather vane is a device for measuring the wind direction while anemometer is a device for measuring the wind speed. A device which can concurrently measure both the wind direction and the wind speed is called aero meter. 3. Ability to integrate the above 2 factors to predict future shift in weather conditions.

127 Lesson 7 Substances and their properties Main learning essence Definition, the importance of substances in everyday life, usage of substances, penetration of substances into human body, types of substances, substances products, the usage of substances in everyday life and their effects, the selection of substances for suitable usage. Expected learning outcome - Be able to explain the importance and need for the use of substances. - Be able to explain general properties of substances. - Be able to classify substances using their status and arrangement of particles. - Be able to explain factors affecting the status of substances. Scope of content Topic 1 Substances and their properties Topic 2 Factors affecting the status of substances.

128 Topic 1 Substances and their properties Defination of substance Substance is an object that exists physically, has a mass, takes space and is able to be touched. Each substance has its own specific properties, called substance properties which are different from those of others such as boiling point of water is 100 degree celcius, the taste of acid is sour, alcohol is flammable etc. Properties of substances can be divided into 2 types as follows: 1. Physical properties are properties of substances that show the external appearance of the substance and are easily noticed such as shape, color, scent, taste, status, boiling point, melting point etc. 2. Chemical properties are properties of substances that show the internal appearance of the substance based on chemical changes such as rust in iron, metal corrosion due to reaction with acid, etc. Status of substances and sorting of particles Status of substances can be classified into 3 types as follows: 1. Solid is a substance that has a certain shape and volume which does not vary with shape of the container. Its particles are closely packed in order. Its density and bonding between molecules are higher than liquid and gas such as rock, wood, plastic, steel, etc. Figure shows arrangement of particles in a solid substance 2. Liquid is a substance that has a constant volume but an uncertain shape depending on its container. Its particles are closely packed but not orderly and collide with each other at all times. Therefore, its density is higher than gas such as water, milk, liquid soap, shampoo, etc. Figure shows arrangement of particles in a liquid substance

129 3. Gas is a substance that has an uncertain shape and volume depending on its container due to its low bonding between molecules. Therefore, it can spread to fill the container and has a very low density such as air, cooking gas, carbon dioxcide, etc. Figure shows arrangement of particles in a gas substance Table 1 Properties of substances in different states Solid Liquid Gas 1. Having mass, requiring space 1. Having mass, requiring space 1. Having mass, requiring space and touchable and touchable and touchable 2. Definite shape, difficult to 2. Uncertain shape depending 2. Uncertain shape depending change shape on container on container 3. Constant volume, unable to be 3. Constant volume, unable to be 3. Uncertain volume, able to be compressed to reduce volume compressed to reduce volume compressed to reduce volume 4. Particles of solid are closely 4. Particles of liquid substance 4. Particles of gas are loosely arranged and unable to move. are closely arranged but there arranged and, therefore, they are some space between can move freely and will always 5. Difficult to pass through particles and, therefore, they can spread out to fill the container. - move. 5. Can pass through 5. Can pass through with ease 6. Surface level of liquid will - always be flat.

Activity 130 Status of substances Gas Tell the status of substances by considering their names then put  in the table. Substance Solid Liquid Rock Table Oxygen Palm oil Cooking gas Fan Saline solution Ice Carbondioxcide Flame Computer Eraser Liquid soap Carbonated softdrink Sugar Nitrogen Alcohol Paper Shampoo Detergent

131 Topic 2 Factors affecting status of substances The status of all substances can change. The change of status involves the temperature, boiling point and melting point of that particular substance. The change of status affects physical appearance of the substance such as ice turns to water, liquid turns to gas, etc. The change of status in various forms are called by different names for each kind of change as follows: Sublimation Absorb 680 cal/g Dissolution Evaporation Absorb 80 cal/g Absorb 600 cal/g Solid Liquid Gas Hardening Condensation Release 80 cal/g Release 600 cal/g Reverse sublimation Absorb energy Release 680 cal/g Relase energy Evaporation is a process in which a substance changes from liquid to gas. This process usually occurs when liquid receives energy or heat without the temperature reaching the boiling point such as water turns to steam. Water in the tea cup evaporates to steam and condenses on the glass. Sublimation is the process in which a solid substance changes to gas without going through a liquid status such as dry ice changes to carbondioxide or if we put Naphthalene in the closet for a long

132 period, it will become smaller due to the change of status from solid to gas that emits the odor to drive insects away. Sublimation of dry ice Condensation is the change of status from gas to liquid that usually occurs when gas loses heat or energy such as steam changing to water, the making of rainfall, etc. Rain Forest, a source of water Land Cloud Atmostphere River Houses Steam Ocean The making of rainfall is due to condensation of steam. Hardening is the process in which the status of a substance changes from liquid to solid which usually occurs when the liquid loses heat or energy such as water changing to ice. On the contrary, a solid substance can change back to liquid when taking energy or heat.

133 Melting or dissolution is the process in which the status of a substance changes from solid to liquid which usually occurs when the solid takes heat or energy such as ice changing to water. Ice Ice melts to water Put water in the freezer; then water changes to ice Crystallization is the process in which the status of a substance changes from liquid to solid which usually occurs when the liquid loses heat or energy such as water changing to ice but generally crystallization usually deals with change in the chemical shape because the crystallization occurs to composite substances or objects that cannot melt back to a liquid status again. Salt Melted salt in water Vaporised water gives salt

134 Activity Changing of status in substances Objective To experiment and explain the change of status in substances. Required equipment 1. Beaker 2. Alcohol lamp 3. Table spoon 4. Salt 5. Ice 6. Matches Directions 1. Divide into small groups of 8-10 learners each. 2. Put ice in the beaker, leave it for 10 minutes. Observe and record the change of ice. 3. Put 1 tablespoon of salt in the beaker then stir until all salt is completely melted. 4. Put the beaker on fire until water completely dries off. Observe and record the change. Experiment records Changes Substance Before experiment After experiment Ice Salt Conclusion …………………………………………………………………………………………………...…………… ……………………………………………………………………………………………..…………………………… …………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………

135 Lesson 8 Separation of agents Main learning essence To gain knowledge about the importance, method and process of separating agents for various uses and to be able to use suitable methods to separate agents. Expected learning outcome 1. Be able to explain the importance, method and agent separating processes 2. Be able to select a suitable method for agent separation and be able to apply the knowledge in everyday life. Scope of content Topic 1Separation of agents Topic 2 Absortion of agents into the human body Topic 3 Types of agents in everyday life Topic 4 Agents and their products in daily use. Topic 5 Effects of agent usage on life and the environment.

136 Topic 1 Separation of agents All substances usually exist together with others in the form of homogeneous or heterogeneous substances. If only a kind of substance is to be used, it may be possible by separating the required substance using specific properties of the substance. The separation of a non homogeneous substance can be done by using physical processes such as picking out, sieve or using magnets. The separation of a homogeneous substance may be done by letting the substance vaporate until it dries out. Pure substance is a homogeneous substance which, when tested, all parts will have identical properties such as distilled water, soda water, syrup, saline solution, etc. Pure substances exist in 3 forms as follows: 1.Pure substances in a solid state such as iron, gold, copper, zinc, aluminum, rose gold, brass, limestone, salt, sugar.. 2.Pure substances in a fluid state such as distilled water, saline solution, vinegar, carbonated soft drink, cooking oil, syrup, milk. 3.Pure substances in the form of gas such as air, gas, oxygen, nitrogen, carbondioxcide. Composite substance is a non homogeneous substance where the additive can be seen with naked eyes. Each composite substance has different properties such as Gruel, mud, antacid, etc Composite substances also existed in 3 states as follows: 1. Composite substances in a solid state such as sand, concrete, soil. 2. Composite substances in a fluid state such as canal water, mud, chicken dipping sauce. 3. Composite substances in the form of gas such as dust in the air, carbon deposit, black smoke in the air.

137 A suitable method must be selected for substance separation based on the properties of the mixed substance. 1.Filtration Filtration is a method to separate solid substances from a composite fluid substance. There are many kinds of materials used for filtration such as paper filter, cotton, white cloth which are used for the filtration of coconut cream, the screening of dust off syrups, etc. Distillation Distillation is a method to separate a fluid or solid substance which are melted together by using their different boiling points. The distillation must transform the fluid substance into vapor through heating. The vaporized substance then condenses to become a pure substance when cooled down. The substance with a lower boiling point will condense before the substance with a higher boiling point.

138 3.Evaporation This separation method is suitable for the separation of fluid substances where a solid substance has melted in the fluid. This method is popular for separating salt off sea water. The salt is taken out when water has completely evaporated. Salt farming using the evaporation method 4.Sedimentation This separation method is used to separate composite substances which have solid substances floating in the fluid substance by leaving the composite substance stand still to settle. The solid particles in the fluid always have a weight and, therefore, after some time it will settle and can be separated from the fluid such as the separation of starch from starch water, soil from mud or the use of alum to wave in the water to make sediments settle etc. Waving alum in water to make sediments settle.

139 5.Crystallization This method is used for the separation of solid composite sunstances by melting them with a solvent until completely melted and then leaving them to settle. The substances which are less able to melt will be saturated and crystallized first such as the separation of sodium chloride from sea water. The crystallization of some minerals 6.Fractional distillation This method is used to separate fluids which have minor differences in terms of their boiling points and, therefore, cannot be separated by conventional methods. Examples of fractional distillations are the separation of water from alcohol (the boiling point of water is 100 degree celcius, alcohol is 78.5 degree celcius) and distillation of untreated water, etc. Low temperature Petroleaum gas Gasoline Nafta Kerosine Diesel, Heavy fuel Crude oil Fuel oil High temperature Bitumen

140 7.Sublimation or Freeze Drying This method is suitable for the separation of solid substances melted in the fluid. For example, when salt is mixed with water we get a homogeneous fluid. If we need to separate salt from this salt water, this can be done by heating the salt water to make water evaporate. The left- over substance in the container is salt. 8.Chromatography This method is used to make a pure substance out of a composite substance by using the following principle “ The fact that individual substances have different melting and absorbtion abilities enables the separation of each individual substance” Topic 2 The penetration of substances into the human body 1. By the nose by means of aspiration of the substance vapor resulting in the toxic fume entering the body together with the air. Some toxic substances have a corrosive reaction which cause inflammation of the nasal tissue and windpipe when inhaled or blood poisoning when infiltrated into the blood stream. 2. By the mouth: This may be the result of carelessness such as using contaminated hands for eating or eating contaminated fruit or vegetables or intentionally taking some kind of poison to commit suicide, etc. 3. By the skin: By touching or holding toxic sunstances. Some poisons can be absorbed into the skin and poison the body. When toxic substances penetrate into the body by any means, with adequate concentration there will be a reaction at the penetration point then after infiltration into the blood stream such toxic substances will be carried to the rest of the body. The ability to enter the blood stream depends on the dissolution properties of the toxic substance. Some toxic substances can be destroyed by the body while some may be driven out by the kidney

141 through the urinal system and the bladder. However, some toxic substances are collected in the liver or remain as fat, etc. Topic 3 Type of substance found in everyday life Type of substance Each type of substance has many properties and each one has different applications. For the convenience of study and use, the type of substance need to be classified.. The classification of substances based on acidity- alkalinity properties The classification of substances based on their acidity and alkalinity properties allows the grouping of household substances into 3 types as follows: 1. Acid substances: This type of substances has a sour flavor and produces a chemical reaction with metals such as zinc producing a chemical reaction with limestone. Examples of this type of substances are vinegar, lime juice, carbonated softdrink, tamarind juice, bathroom cleanser, etc. 2. Alkaline substances:. This type of substances has a bitter flavor and are slimy when rubbed on the palm, produce a reaction with fat, vegetable or animal oil resulting in soap production. Exaples of this type of substances are limewater, caustic soda, ash water. When alkaline substances are tested with red litmus, the color will change from red to blue. 3. Neutral substances: This type of substances has many properties and when they are tested with the litmus, there will not be any change in the color of the litmus.Examples of this type of substances are water, saline solution, syrup, etc. Topic 4 Substances and substance products in daily use Classification of substances based on their benefit of use 1. Cleansing agents: There are many kinds of such substance such as - Cleansing agent for cleaning various parts of the body such as soap, toothpaste, shampoo, mouthwash. - Cleansing agent for cleaning cloths such as laundry soap, powder detergent, stain remover.

142 - Cleansing agent for cleaning utensil such as dishwasher liquid, specific kinds of cleanser such as window cleaner liquid, bathroom cleanser. 2. Substances for use in agriculture Pesticide which farmers spray on crops to eliminate pests is a popular substance used in agriculture This kind of substances is harmful for human beings, animals and the surrounding environment. Therefore, they must be used carefully and should not be used excessively. 3. Medicinal substances: These substances used for the treatment of diseases or illnesses can be categorized into 2 types based on their usage as follows:. - Internal medicine such as red or white color stomachic tonic, Paracetamol, Black color cough syrup, Soda mint pill. - External medicine such as Acriflavine, Merbromine solution, Collyrium, Alcohol. 4. Household insecticide: These substances can have both fuming, spraying and powder properties such as Mosquito repellent, DDT. Food flavoring agents: There are many kinds of such substances which we use in cooking such as sugar, fish sauce, soy sauce, other kinds of sauces , vinegar. Topic 5 Effects of substance usage on life and the environment Danger from poisoneous substance usage The improper use of poisoneous substances can be harmful to human beings and the environment as follows 1. Causing danger to consumers directly such as for farmers who work in factories where poisoneous substances are used as well as the general public due to the lack of understanding and knowledge concerning their proper use and prevention against such hazards leading to accidents. For example the toxic substance used may get into contact with the user’s body or poisoneous gas leaking into the air may be inhaled, leading to fatal risks or illnesses immediately or in a cululative basis as it accumulates in the various body organs causing the body to become weary and seriously ill.. 2. Causing danger to the life and health of the general public and other living things in the surrounding area where the toxic substance is used.

143 3. Causing the loss of the natural balance of the environment because some insects which are useful for eliminating pests which are dangerous for plants, human beings and animals become extinct. At the same time, some problematic pests such as bugs can have their immunity to the toxic substance improved, causing them to become even disseminated. Some pests that have not existed before may also start to spread out, causing more problems. 4. Causing life threatening dangers to birds, fish, various wildlives and some useful insects such as bees the quantity of which has been decreasing while some insects are close to extinction. This is due to the immediate death caused by toxic substances or the accumulation of such toxic substances in their body which leads to reproduction problems. 5. Causing long-term dangers to all living things and human beings because the residual toxic left-overs in food and the environment get accumulated into the body, leading to the malfunction of the various human body systems which may result in serious illnesses or mutations or disorders in the next generations. 6. Causing economic losses for the country as people who fall ill cannot be fully effective and treatment costs are also costly. Moreover, the country may be unable to export food and argricultural products due to excessive levels of residual toxic substances. 7. Causing damage to the environmental quality. Toxic substances released and left over in the environment such as poisonous substances and heavy metals in water resources or poisonous gas mixed in the atmosphere which may cause so much damage to the environment that it becomes unsuitable for all living things.. Preventive measures when using toxic substances. 1. Try to avoid the use of toxic substances in any activities 2. It is necessary to study and understand the dangers relating to each type of chemical substance. 3. Use protective tools and equipments when working with chemicals. 4. Arrange for people who work with chemical substances to have medical check- ups at least once a year. 5. Avoid areas where chemical substances are used to prevent toxic substances from getting into body by the mouth.

144 6. When dealing with chemical substances, the label should be studied thoroughly and the instructions and warnings must be strictly followed. 7. Containers of chemical substances or the spraying machine shall not be washed in the river, stream, pond, canal etc 8. Destroy and bury chemical containers after use.. 9. Cooperation with the public administration in controlling the use of chemical substances and all public relations efforts relating thereto.

145 Activity Filtration Objective Be able to do the experiment and explain the separation of substrances by filtration Equipment needed 1. Beaker 2. Filter Funnel 3. Filter paper 6. Water 4.Distilled water bottle 5. Tapioca flour 7. Glass stick Directions 1. Learners shall be divided into groups of 4 - 5 learners each. 2. Pour water into the beaker and mix tapioca flour in the water. Stir until the tapioca flour is completely blended in. 3. Fold the filter paper and put it in the filter funnel. Then use the distilled water bottle to spray water on the edge of the filter paper to make it wet to ensure that the filter paper sticks to the filter funnel. 4. Pour the tapioca flour solution into the filter funnel, record the result of the experiment. Recorded result Observed results Substances 1.Tapioca flour solution 2.Filtered tapioca flour solution Conclusion of the experiment …………………………………………………………………………………………………... ………………………………………………………………………………………………………….. …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… ……………………………………………………………………………………………………………

146 Lesson 9 Substances in everyday life Main learning essence The relationship between substances in everyday life. How substances penetrate into the human body. Pros and cons of substances. Classification of substances and substance products found in everyday life. How to choose substances which are useful to life and the environment. How to select and purchase substances properly. Expected learning outcome - Be able to explain properties of substances in everyday life. - Be able to explain the penetration of substances into the human body. - Be able to classify the types of substance and substance products found in everyday life. - Be able to explain the usage of substances in everyday life and in the environment. - Be able to explain the principle for buying and choosing substances. - Be able to buy and use substances suitably. Content scope Topic 1 Properties of substances used in everyday life. Topic 2 Substances and their products used in everyday life. Topic 3 Choosing, buying and using substances safely.

147 Topic 1 Properties of substances used in everyday life. In our everyday life, we need to use various substances all the time. Some substances are beneficial for our body such as food, medicines, cleansing products, etc. However, even though some substances may be beneficial but they may also be detrimental to the environment such as insecticides, pesticides or various man-made gases. Substances used in everyday life can be classified into the following types: 1. Acidity – Alkalinity: Substances may be classified based on their acidity - alkalinity properties as follow 1.1 Acid substances: These substances have a sour taste and produce a chemical reaction with metals and limestone. When tested with a blue litmus paper, the color will change to red. The PH value is between 1-6. Examples of the acid substances are lime, vinegar, bathroom cleaners, etc. 1.2 Alkaline substances: These substances have a bitter taste and when tested with a red litmus paper the color will change to blue. They are also slippery when touched and produce a reaction with fat or vegetable oils and have a PH value between 8-14. Examples of such substances are laundry detergent, soap, ash water, etc. 1.3 Neutral substances: These substances will not change the color of the litmus paper when tested. The PH value is 7. Examples of such substances are drinking water, saline solution, etc.

148 Activity Acidity - Alkalinity test Objective Be able to test and explain the acidity and alkalinity of substances. Equipment needed 2. Droppers for each solutions 1. Solutions (see table) 4. Litmus papers 3. Clock glass or glass container 5. Tray with compartments Directions 1. Drip 3 drops of the prepared solutions in each compartment of the tray. 2. Dip the litmus paper in the solutions, compare the color of the litmus, leave tested litmus on the clock glass or glass container and record the result. Recorded test results Substances Properties of substances Color Acid Neutral Alkaline Liquid soap Laundry detergent Vinegar Carbonated softdrink Dish washing liquid Saline solution Lime juice Bathroom cleaner Drinking water Cement water Conclusion of the experiment ………………………………………………………………………………………………….. …………………………………………………………………………………………………………… ……………………………………………………………………………………………………………

149 Topic 2 Substances and substance products used in everyday life 2.Catagorizing types of substances The type of substances can be categorized according to their properties and usage as follows: 2.1 Cleansing substances: This type of substances is used widely in everyday life. There are cleansing agents that are used to clean the human body, clothings or dishes such as soap, detergent, toothpaste, bathroom cleanser, etc. 2.2 Argricultural substances: This kind of substance is mostly used to eliminate pests such as insects and weeds. Excessive use or this kind of substance may affect the users and the consumers. Moreover, such substances also polute the environment.

150 2.3 Medicines: These substances are used to treat and cure human illnesses. They can be divided into two types as follows: Internally used medicine such as Paracetamol, Stomachic Mixture, cough syrup, etc. Externally used medicine such as Mercurochrome, eye drops, alcohol, etc. 2.4 Additives There are many kinds of food additives based on the purpose of use as follows: Flavoring agents - Fish sauce, Soy sauce, other sauces Coloring agents - Food colors, natural colorings Artificial scents Food preservatives - Preservatives 4.5 Beautification substances There are many substances which are used as beauty products or cosmetics depending on the purpose of use such as skin nourishing products - skin lotions, food supplements, etc.