A.Tick the correct answer:- 

1.c 2.a 3.b 4.a 5.d

B. Differentiate between the following:-

1. Monomer is made up of 1 unit while polymers are made of more than one monomer.

2.natural fibres are natural obtained while synthetic fibres are man made.

 e.g. natural fibre-- cotton, jute 

 Synthetic fibre-- rayon, nylon

3.Thermosetting plastics once set do not soften  on heating and cannot be reshaped. They are often very tough materials with high melting points.

     Thermoplastics soft and easily on heating and can be remolded into new shapes.

C. Give one word answer for each of the following:-

1. Polymer 2. Rayon 3. Thermosetting plastic

4. Acrylic 5. Photo plastic

D. Match column A with column B:-

1. Monomer 2. Wood pulp 3. Acrylonitrile

4. Acrylic plastic

E. Give two examples for each of the following:-

1. Rayon, Nylon 2. Polythene, Bakelite

F. Give reason for each of the following:-

1. Because they are cheap, long-lasting and easily washable.

2. Because bakelite is non conductor.

3. Because blended fabrics overcome some of the drawbacks of synthetic  fabric.

G. Write True or False:-

1. False 2. True 3. True 4. False 5. False

H. Circle the odd one out:-

1. Ethylene 2. Plastic 3. Melamine

I. Fill in the blanks:-

1. Thread 2. Wool 3. Mr.Shivers and Mr. Sandquist 4. Monomer 5. Bakelite

J. Short- Answer Questions:-

1. Synthetic fibres are man made fibre e.g  rayon, nylon etc.

2. Natural polymer-- Silk,Wool.

Synthetic polymer-- Rayon, Nylon.

3. Rayon is made by combining thousands of cellulose unit.

4. Monomer of polyester is ester molecule.

5. Properties of plastic are:-

(a). Non reactive.

(b). Light, strong and durable.

(c). Poor conductors.

(d). Particular chemical reactivity as not affected by acid and alkalies.

K. Long- Answer Questions:-

1. Plastic have both advantages and disadvantages, hence they are both a blessing and curse.

Advantages of plastics are:-

(a). Inexpensive.

(b). Do not corrode or rust.

(c). Easy to make on a large scale.

(d). Easy to mould into any shape.

(e). Do not conduct heat and electricity.

Disadvantages of plastics are:-

(a). Inflammable.

(b). Non biodegradable.

(c). Pollute the environment.

(d). Harmful to animals.

2. Properties of Nylon are:-

(i) It is light weight and strong.

(ii) It is stretchable.

(iii) It is durable.

(iv) It dries quickly.

(v) Easy to clean.

(vi) Does not absorb moisture.

Uses of Nylon are:-

(i) As hosiery product.

(ii) In umbrellas, sleeping bags, tents etc.

(iii) In making parachutes, tyre cords, seatbelts etc.

3. Properties of polyester are:-

(i) It is strong and durable.

(ii) Does not wrinkle.

(iii) Resistance to crease.

(iv) Resistance to most chemicals.

(v) Can be easily washed.

(vi) Does not absorb moisture.

Uses of polyester are:-

(i) As dress material like jackets sportswear etc.

(ii) As curtains floor covering etc.

(iii) P E T is a form of polyester used to make bottles films wires etc.

4. Properties of acrylic are:-

(i) It is easy to wash.

(ii) It is soft and lightweight.

(iii) Easy to be dyed.

(iv) Does not shrink , wrinkle.

(v) It is cheaper than wool.

Uses of acrylic are:-

(i) Making sweater, socks, sports wear etc.

(ii) Making blankets and rugs.

Properties of spandex are:-

(i) Highly elastic.

(ii) It is a strong but not as durable as other synthetic fibre.

Uses of spandex are:-

(i) Making leggings, swimsuit etc.

(ii) Making surgical hose etc.

5. Plastics are another form of long chain polymer

A. Uses of thermoplastics are:-

Polythene- Making containers, toys, pipes for transporting liquid.

PVC- Insulation cover of electric wires.

Teflon- Coating on cooking ware.

B. Uses of thermosetting plastics are:-

Bakelite- As insulating material containers etc.

Melamine- Dinnerware, decorative objects.

6. Plastic is a non biodegradable substance which cannot be turned into to useful and nature friendly products. The bacteria or microorganisms just can't break them up. when it is eaten by animals it gets stuck in the stomach and makes them sick because the bacteria in their stomach can not break the plastic into smaller pieces. When plastics are burnt they give out toxic fumes which is harmful to healthy.

          For managing in plastic we use 4 R  principal as-

Reduce- Reduce the use of plastics.

Reuse- Reuse materials made of plastic instead of throwing them away.

Recycle- Recycling is another way of managing plastics.

Recover- Recover plastics for recycling.