Plastics take several years to decompose, so they are not environment-friendly. Plastic causes environmental pollution. Besides, the burning process of synthetic material is quite slow and it does not burn completely. In this way, it releases lots of poisonous fumes in the atmosphere causing air pollution.

The 4Rprinciple means Reduce, Reuse, Recycle and Recover. One should develop these habits, which are environment friendly.

Plastic is very strong, light and durable. It can be moulded into different shapes and sizes. It is used for various purposes. Plastics are generally cheaper than metals. They are widely used in industry and for household articles.

When plastic is left exposed to moisture and air it is not corroded easily. So they are non-reactive.

Plastic containers seem most convenient because of their light weight, lower price, good strength and easy handling.

(i) Synthetic fibre soaks less water, whereas natural fibre soaks more water.
(ii) Natural fibre.
(iii) Synthetic fibre.

Disadvantages of synthetic fibres are :
(i) It melts on heating.
(ii) Its clothes catch fire easily
(iii) It melts and sticks to the body of the person wearing it, when it is heated.

Plastic is non-reactive material. When left exposed to moisture and air, it does not react with air and water which are essential for corrosion, therefore does not rust

Plastics are poor conductors of heat and electricity. So, handles of cooking utensils (like frying pans and pressure cookers) are made up of plastic so that we can hold the hot utensils safely without getting our hands burnt.
Plastics are poor conductors of electricity. So, electrical wires have plastic covering and handles of screw drivers (used by electricians) are made up of plastic, so as to protect us from electric current passing through them.

Properties of nylon are:
(i) Nylon is a synthetic fibrous material that is known for its high tensile strength, abrasion resistance and chemical stability.
(ii) It is a very resilient fibre that is often used to make cords and ropes that need to support a lot of weight and withstand in wet, hot or dirty condition.
(iii) When used in clothing, nylon is both light weight and warm.

Take two wires. One wire is kept naked and another wire has plastic covering. Make two circuits, one with naked wire and another with plastic covering. We will feel shock with naked wire while plastic covered wire will not give any shock.

It shows that thermoplastic is a poor conductor of electricity.

We should avoid plastics as far as possible because plastics are non-biodegradable materials. Plastics take several years to decompose, thus cause environmental pollution. Burning of plastics releases poisonous gases into the atmosphere causing air pollution.

No, handle and bristles of a toothbrush should not be made of the same material because the handle should be hard while bristles should be made of the soft materials. Bristles should be soft so that it does not harm the gum of teeth. Handle should be made of hard material so that it gives the firm grip.

Advantages of storing foods in plastic containers are as follows:
(i) Plastics do not react with food items.
(ii) Plastics are strong, light and durable.
(iii) Plastic containers are airtight.
(iv) They are easy to handle.

Nylon fibres are very strong. Thus, they are used for making parachutes and ropes for rock climbing. A nylon thread is actually stronger than a steel wire.