Let's Find out about Materials and their Properties !

Relationship between the properties of materials and their uses

Objects around us are made of different materials. We choose materials to make objects based on their properties of the materials that we were using.The objects that are made of the right materials will be very useful. Some useful properties of materials are the degree of transparency to light, magnetic property, heat conductivity and electrical conductivity.


Let us look at how the materials with these properties are used for making objects.








Uses of materials based on their heat conductivity

Materials that are good conductors of heat are used to make object that allow heat to pass through them quickly. Materials that are poor conductors of heat are used to make object that prevent heat from passing through them. Poor conductors of heat are also called insulators of heat. 

Steel , iron and other metals are used to make the body of pots and other cooking utensils to cook food quickly.

Uses of materials based on their degree of transparency to light

Materials which are transparent to light allow most light to pass through them. Transparent materials are used to make objects that can see through, such as windows. Materials that are opaque do not allow light to pass through them. Opaque materials are used to make objects such as doors and walls. Doors and walls of buildings need to be opaque to protect our own privacy.

Uses of materials based on their electrical conductivity


Materials that allow electricity to flow through them are used to make objects that conduct electricity. Materials that do not conduct electricity are used to make objects that prevent electricity from flowing through them. Two or more types of materials may be found in the same object. They are used to make different parts of the object. 

 

 Uses of materials based on their magnetic property
Magnetic materials and magnet work together to hold objects together.





Not all materials have properties which are suitable for making object. Do, when we are choosing materials to make an object, we need to know the :

• Properties of the materials.
• Use of the object. 

Let us look at some examples of common materials, their properties and their uses.

Sink

A sink must not absorb water. It must keep a fixed shape. The material we use to make sink must be :

• Waterproof.
• Strong.
• Hard.

As ceramic has these properties, it is used to make the sink.

Drinking bottle

A drinking bottle must not absorb water or break easily. It must be easy to carry around. The materials we used to make the drinking bottle must be :

• Hard
• Waterproof
• Light

As plastic has these properties, it is used to make the drinking bottle.

Bench

A bench must be able to support heavy weights and not bend. The materials we use to make the bench must be :

• strong
• rigid

As metal has these properties, it is used to make the bench.

Windows

Floor-to-ceiling windows must stay upright, keep a fixed shape and allow most light to pass through it. The material we use to make floor-to-ceiling windows must be :

• hard
• rigid
• transparent

As a glass has these properties, it is used to make floor-to-ceiling windows.

Treadmill belt

The walking belt of a treadmill must be bend easily and cushion the steps of a person. The material we use to make the walking belt must be :

• flexible 
• soft

As rubber has these properties, it is used to make the walking belt of the treadmill.

Materials are also used to make household items such as bleach, pesticide and medicine. Although these items are useful, they may also be poisonous. So, to keep everyone safe from harm, we need to handle them correctly. We can do this by :

• labelling them properly
• using them for their intended purpose
• keeping them in suitable places
• disposing used materials properly

Labelling household items properly 

 To keep everyone safe, it is very important to label hazardous, and essential household items properly. 

Sometimes, we may see the international warning signs for chemicals on certain household items. These warning signs let us know the dangers of the chemicals.  For example, aerosols are flammable and are usually labelled with  the warning sign for flammable materials.

Using household items for their intended purpose

Should follow the instruction on the label of a household item. Using the household item only for its intended purpose. Using the correct quantity of the household item. Using a household item in the wrong quantity or for the wrong purpose can be dangerous. Chemicals in the household item may react with other chemical to produce poisonous products. We need to ensure we do not mix or use materials for purposes other than what they are meant for.

Taking medicine, we should follow the instruction on the label, because taking more medicine than what is necessary may cause poisoning.

The label also tell us what the medicine is for. Taking the wrong medicine for our illnesses can worsen our condition. We should not share our  medicine with others or take another person's medicine.

 

Keeping household items in suitable places

Always follow the storage instruction on the label found on household items.Proper storage of household items ensure that the chemical in the household item do not  mix and  cause poisonous substances to form.
Household item should be kept away from food to avoid contamination of food.Should not keep household item in container that look like food container.
We should keep household item containing corrosive and flammable chemicals in separating places. If these household items are stored together they might mix and react to form poisonous gases or cause fires.
Should store flammable and volatile chemicals in cool areas away from sunlight and other sources of heat such as stoves.
Should store corrosive chemicals away from metallic objects as they can cause metals to corrode.

Disposing of used materials 

Household items are no longer useful to us, they become waste or used materials, which we also need to dispose of properly. We produce different types of waste. Types of wastes include recyclable waste, non-recyclable waste and chemical waste.
Let us look at how we should dispose each type of waste.

Disposal of recyclable materials

Recyclable materials such as paper, metals and plastic should be dispose in recycling bins. We should not throw non-recyclable materials into recycling bins.

Disposal of chemical waste

Old paint, old aerosol sprays, expired medicine and household cleaning liquids contain unwanted chemicals or chemical waste. Chemical waste is harmful to our health and can pollute our water supply. May even cause explosions if it mixed with other chemicals.


Here are some ways we can dispose of chemical waste safely.


Make sure that aerosol spray cans are completely empty by pressing the button top of the cans before throwing them away. This releases any gas left in the cans.


We should make sure that leftover paint is completely dry before disposing it.


Wear gloves when disposing household cleaning liquids such as bleach or window cleaners. These liquids contain chemicals which irritate our skin. 


We should return expired medicine to local pharmacy for proper disposal. Should not flush it down the drain.