2. Materials at Home What materials does your mother use when
she prepares food? What do you use when you find the food
tasteless? What are things in your home that are made of plastic?
Do you use and dispose of these things properly? There are
different materials found in your home. They are in different
states and shapes. Some are in solid state, others are in liquid or
in gaseous state. This chapter gives you information about
household materials, their useful effects as well as harmful
effects, their proper use and disposal and their structure.
3. Useful Household Materials LESSON 1
4. Look at the materials shown below. These materials are all
found in your home. They are used for cooking, for personal
grooming and medicinal purposes. What are some other household
materials and their uses? Find out in this lesson.
5. There are lots of materials that you have in your home
according to their purpose. Lets identify these materials and their
uses.
6. Preservatives Have you seen your mother putting some salt on
a fish or chicken before storing it in the refrigerator? Have you
seen a fish soaked in vinegar? Salt and vinegar are used to prevent
the fish and chicken from spoilage. They are called preservatives.
Preservatives are substances that are used to prevent the action of
the agents of spoilage such as bacteria, molds, yeasts, and
insects. Today preservatives such as sodium nitrate and sodium
benzoate are used to preserve food packed in cans, bottles or
plastics.
7. Additives Aside from preservatives you would also see
materials that are used to enhance the taste and color of food you
eat. These are called additives. Achuete is a natural additive used
in foods that are cooked such as apritadang manok and menudo so
that they become colorful. Cakes, puddings, puto and other colorful
foods you buy have additives.
8. Soap and Antiseptic Soap is a substance, ususally made by
the action of alkali on fat, that dissolves in water and is used
for cleaning and washing. Soap is an antiseptic. Antiseptics kill
germs and prevent them from spreading diseases. Soap is not only
used in cleaning or washing your body but is also used for washing
kitchen utensils and other things in your home. There are different
brands and fragrances of soap. Name some.
9. Detergent and Shampoo A stronger variety of a soap is a
detergent. It can dissolve grease and natural oils. Shampoo is a
special antiseptic. It is commonly used for cleaning hair..
10. Solvents Solvents are liquids that dissolve another
substance or substances for a solution. Water is a universal
solvent. Besides water, there are other examples of solvents.
Solvents that are used to remove stains in clothes are vinegar and
calamansi juice extract. Both of these substances contain acid.
Muriatic acid is an effective solvent in removing stains in kitchen
sinks and bathroom tiles. Acetone is used to remove nail polish.
Alcohol is used to remove permanent ink on a white board. Thinner
is used to dissolve solid materials in paint.
11. Pesticides Pesticides are chemical mixtures or botanical
agents from plants. Farmers use pesticides to protect crops. Pests
may cause crops to rot or even cause its death. We should be
careful in using pesticides. Pesticides become harmful when they
contaminate ground water. They even cause cancer.
12. Insecticides Insecticides are chemicals used to kill
insects. These are used to kill flies, cockroaches and mosquitos.
What insecticide do you use at home?
13. Paint Paint is a mixture or coloring matter with a suitable
liquid that forms a dry coat when spread over a surface. Paints are
used to prevent the iron from combining with oxygen and moisture in
the air. They prevent rusting. Paints also beautify and help
protect things from wear and tear. Why are your window grills,
wall, furniture, roof and house painted?
14. Synthetics and Plastic Synthetics are substances that have
been made artificially. They come from carbon, hydrogen, nitrogen
and oxygen. They are changed into near materials through chemical
processes. Plastic is an example of a synthetic material that is
widely used nowadays. It is a factory made material that can be
molded into different shapes. It was first made in the United
States about 90 years ago. It is strong and can be bright and
colorful. It is very useful because it doesnt fall apart easily or
rust in the open air. There are several plastic materials that we
use now. Give some examples of plastic materials.
15. Remembering Science Facts There are different household
materials for different purposes. Some materials at home are
preservatives, additives, pesticides, insecticides, antiseptics,
plastics, solvent and paint. Synthetics are substances that are
artificially creates from chemicals.
16. Match column A with column B. Write the letter of the
correct answer. A B 1. Prevent spoilage of food a. Additives 2.
Prevent things from rusting b. Detergents 3. Remove tough grease
and stains on clothes c. Fungicides 4. Made buy the actions of
alkali on fat and used for cleaning and washing d. Insecticides 5.
Enhance tastes/color of foods e. Paints 6. Kill insects f.
Pesticides 7. Kill pests that destroy crops g. Preservatives 8.
Used to dissolve other substances h. Shampoos 9. Artificially made
from chemicals i. Soaps 10. Antiseptics used for cleaning hair j.
Solvents k. Synthetics
17. What are the useful materials in your household? Household
Material Examples Use 1. Additive 2. Preservative 3. Antiseptic 4.
Solvent 5. Insecticide 6. Plastic 7. Pesticide
18. Materials Improved by Technology and Their Useful Effects
LESSON 2
19. What is technology? Technology is the application of
science to practical human ends- particularly to improve the
quality of life. It is used to develop new products. People in the
ancient times had simple living. They used simple shelter, clothing
and tools. Nowadays, technology has improved mans life to a great
extent. In agriculture, technology has improved crop yields with
the invention and use of farm machinery and new farming
techniques.
20. Our means of transportation and communication have had
profound changes too. You have mobile phones, cordless phones,
computer, laser, internet and MRT that make life more convenient.
Canned goods and ready-to-eat foods have become plentiful. The
availability of these food help save time. It also helps people who
spend more time working outside their homes. Synthetic materials
have gone a long way too. Most of the materials you use today such
as the appliances, furniture, utensils and many more are found
almost everywhere. All these things are products improved by
technology.
21. What are the materials in your home that are improved by
technology? Name of the Material Old Material New Material e.g.
eating paraphernalia Ceramic plates Plastic plates Disposable
plates styrofoam What are the improved materials made of?
22. Plastic Technology Technology has done a great improvement
to most of the materials we use everyday. One example is the
extensive use of plastic. Plastic usually refers to solid materials
that become soft when heated. At this stage, the material can be
molded into shapes and is used to make household objects. Nowadays,
the word plastic usually refers to a group of synthetic polymers.
Plastics are made by joining molecules together in chains. Each
unit of the chain is called a monomer. When monomers are joined
together, they are called polymers. Polymer comes from two Greek
words, poly meaning many and mer meaning unit. Most often,
materials that used to be made from natural materials such as wood
or metal are now being produced with the use of plastics. Why are
there numerous plastic materials now?
23. There are lots of kinds of plastics. There are plastic
materials that are very strong and heat-resistant. They are used
for frames, windows and paint. Some are used for switches,
electrical tools and kitchen appliances because they are resistant
to heat and moisture. Hard plastics are used to make crash helmets
and chairs. Plastic is used to strengthen other materials such as
fabric or clothes. Plastic is easy to clean and hard to break. It
is used for food packaging and to make plates, knives and forks.
Plastic is not harmed by rain so it is used to make telephone
booths. Soft plastics are used to make shower curtains and trash
bags. Polystyrene, better known locally as styrofoam, is a
thermoplastic used in making individual food boxes, ice boxes,
disposable glasses, bowls and plates. Thermoplastic is a form of
plastic which is softened by heat and can be formed again and again
so long as the heat does not burn up the material. Thermosetting
plastic, another form of plastic, does not soften upon heating. The
plastic sheet used in laminating wood frames and table tops and the
spongy material used for scrubbing dishes are thermosetting
plastics.
24. Remembering Science Facts Technology improves the quality
of materials for our homes. Some materials make living more
comfortable.
25. Did you know that Some kinds of plastics are safe to use
inside the human body. When people break their bones in an
accident, the broken bones may be joined together again by plastic
screws and pins. Surgeons use plastics to replace damaged organs
such as the heart. The black lining inside a non-stick saucepan is
a kind of plastic.
26. Label the plastic products below:
27. Conditions When Materials Have Harmful Effects LESSON
3
28. Can you identify the materials shown below? Which of these
materials do you often use? Are they useful all the time? When do
they become harmful?
29. What are the conditions when materials have harmful
effects? Discuss the photos below.
30. Technology has improved most of the materials we use at
home. However, it created serious problems. Technology has resulted
in many forms of environmental pollution, including toxic
industrial waste, air pollution from motor vehicles, destruction of
ecosystem by the use of insecticides, and thinning of the ozone
layer.
31. Water Pollution Detergents, chemical waste, excess
fertilizers, pesticides and insecticides that go to the rives and
lakes pollute the water. Detergents such as those in bars or powder
used for washing clothes, powder or gels that disinfect and kill
germs, and dishwashing liquids are the agents that pollute our
environment. They tend to remain in water and resist conversion
into less complex substances. The detergents components just go
down your household drains, into the canal, then into the lakes and
other bodies of water. Untreated sewage from industries contain
disease-causing bacteria and toxic chemicals. Inorganic fertilizers
and pesticides are both made from chemicals. When they are used
carelessly, they may also pollute water and affect not only humans
but also the animals and plants that live in water.
32. Most plastics that we dump into rivers are
non-biodegradable. There are no microbes that use them as food when
they are dumped as waste. So they cause pollution.
33. Air Pollution Fumes that public jeepneys and buses emit
contain poisonous substance like carbon dioxide. Lead which is
added to gasoline to make engines run better is harmful too.
Harmful gases such as carbon monoxide, sulfur dioxide and nitrogen
oxide that come from the burning of fuels in big factories also
contribute to air pollution.
34. Thinning of the Ozone Layer Chlorofluorocarbons (CFCs) are
gases which contain atoms of chlorine, fluorine, and carbon. CFCs
are used as coolants in air conditioners and refrigerators,
propellants in aerosol spray cans, cleaners for electric parts such
as computer chips, building blocks for the bubbles in Styrofoam and
used for insulation and packaging. CFCs are useful but they damage
the ozone layer in the Earths atmosphere. Ozone layer in the
stratosphere protects us from the harmful effects of ultraviolet
radiation from the sun. However, it has been observed that there is
a hole In the ozone layer above the South Pole and neighboring
areas. What would be the effect of this hole to humans?
35. Ozone Layer
36. Remembering Science Facts Some materials have harmful
effects on the environment. Detergents, pesticides, plastics,
inorganic fertilizers, household and industrial wastes that go to
the rivers pollute water. Chlorofluorocarbons (CFCs) cause the
thinning of the ozone layer.
37. Supply the missing words in the paragraph. A. Up in the
______ above the air we breathe, there is a _________ of gas called
OZONE. It helps us by blocking out the rays from the ______ that
can harm our _______. Now the ozone layer is being damaged by _____
made gases. These gases are called chlorofluorocarbons. They are
used in ___________, _____________, ______________, and some other
things.
38. Supply the missing words in the paragraph. B. Some
household materials have harmful effects on living things.
___________ that is used in _______ and cleaning as well as
chemicals that go into a _________ and other bodies of __________
can pollute them. As a result, ______ and _______ that live in
water are being killed.
39. Safety Precautions in the Use and Storage of Materials
LESSON 4
40. Safety Precautions in the Use and Storage of Materials The
materials found at home are very useful and important. They become
useful when you know how to use them and where to keep them safely.
However, if they are not used properly, they become dangerous and
may cause accidents.
41. Here are some safety precautions in using materials. Only
food should be tasted. Never attempt to taste unknown materials.
Read labels and instructions on containers before using any
material. Avoid using expired canned goods, medicines and other
packed foods. Wash your hands after using chemicals. Wear safety
gloves if your skin is sensitive to strong detergents or when
cleaning materials contain acid. Wear protective goggles or a mask
when using chemicals. Hold the chemicals away from your eyes.
Always use a spoon when transferring solid chemicals and dropper
for liquids. Prepare clean rags for wiping up spilled chemicals.
Medicines should not be taken in carelessly, especially by
children. Never play with flammable materials.
42. The following are some useful tips in storing materials:
Lysol, acids, bleach, pesticide, kerosene and other dangerous
chemicals must be properly labeled and sealed. If possible, put
appropriate symbols for danger on the container such as the symbols
below: FLAMMABLE TOXIC RADIOACTIVE
43. Storage Tips: Avoid using empty food containers to store
chemicals. Chemicals such as cleansing agents must not be placed or
stored together with food items. Chemicals should be stored in a
cabinet beyond the reach of children. Combustible materials such as
lacquer thinner, kerosene and other petroleum products should be
kept away from the stove to prevent fire. Materials for food
preparation and food condiments should be tightly closed and stored
separately from cleaning materials. Keep them in a dry place.
44. For proper disposal of materials: Separate wet from dry
garbage. Recyclable materials such as tin cans, newspapers, plastic
bags and bottles should be placed in separate containers. Label
expired medicines and corrosives before putting them in the
garbage. Reducing, recycling and reusing materials helps to lessen
pollution in our environment.
45. Remembering Science Facts Safety precautions should be
observed in using/storing/disposing household materials.
46. Check which are the proper ways to use or store materials.
1. Smell and taste unknown materials before using them. 2. Read
labels before using chemicals. 3. Store cleaning materials together
with other chemicals used for food preparation. 4. Cover food
condiments tightly. 5. Keep petroleum products near the store. 6.
Keep chemicals in a cabinet within the reach of children. 7. Store
expired materials. 8. Wear rubber gloves when using strong
chemicals. 9. Wash your hands after using chemicals. 10. Hold
muriatic acid with your bare hands.
47. Structure of Matter LESSON 5
48. Structure of Matter A material whether solid, liquid or gas
is made up of tiny particles called molecules. These molecules
exhibit the properties of the substance itself. For example, a drop
of water can be separated into its smallest particles and can still
be identified as water. The smallest drop of water is a molecule of
water. Molecules are still composed of smaller particles which
cannot be seen. These small particles are called atoms. A molecule
may be made up of one or more kinds of atoms.
49. Solids, Liquids, Gases Molecules of one substance are
different from the molecules of another substance. The molecules of
water are different from the molecules of sugar. The molecules of
sugar are different from the molecules of gas. Let us find out how
the molecules of solids, liquids and gases differ from one
another.
50. How are the molecules of a solid, liquid and gas arranged?
Observe the differences and discuss.
51. Solid The molecules of solids are arranged very close to
one another. They keep the shape of the material they are in. Their
movement is limited. The particles in a solid state can only move
back and forth. They cannot change the amount of space they occupy.
Thats why the pebbles move back and forth but not far from one
another.
52. Liquid The molecules of liquids are arranged a little
farther apart than those of solids. Their molecules can move more
freely than those of solids. They may slide against one another. As
a result, liquids flow and take the shape of their container. This
is shown in cup B.
53. Gas Cup C represents the arrangement of molecules in gases.
The pebbles in cup C move more freely and hit one another. The
molecules of a gas are arranged farther apart from one another. The
molecules spread out and occupy all available spaces. They can move
more freely and rapidly than solids and liquids.
54. Remembering Science Facts Molecules in solids, liquids and
gases are arranged differently. The molecules of solids are
arranged very close to one another. The molecules of liquids are
arranged a little farther apart than in solid. The molecules of gas
are arranged farthest apart from one another. A molecule is the
smallest particle of a substance which exhibits the properties of
that substance.
55. Identify the phases of matter. (Solid, Liquid, or Gas) 1.
Takes the shape of its container 2. Molecules spread out and fill
all available spaces 3. Rigid and firm 4. Has a definite shape 5.
Molecules are very close to one another 6. Move more freely 7. Can
flow 8. Has no definite shape and volume 9. Movement is limited 10.
Molecules are arranged farthest apart
56. For you to remember There are different household materials
for different purposes. Some materials at home are preservatives,
additives, pesticides, insecticides, antiseptics, plastics,
solvents and paints. Synthetics are substances that are
artificially created from chemicals.
57. For you to remember Technology improves the quality of
materials for our homes. Some materials make living more
comfortable. Some materials have harmful effects on the
environment. Detergents, pesticides, plastics, inorganic
fertilizers, household and industrial wastes that go to the rivers
pollute water. Chlorofluorocarbons (CFCs) cause the thinning of the
ozone layer. Safety precautions should be observed in
using/storing/disposing household-materials.
58. For you to remember Molecules in solids, liquids and gases
are arranged differently. The molecules of solids are arranged very
close to one another. The molecules of liquids are arranged a
little farther apart than in solid. The molecules of gas are
arranged farthest apart from one another. A molecule is the
smallest particle of a substance which exhibits the properties of
that substance.