Science Question Answer (2 Marks)

Acrylic is a synthetic fibre which appears to resemble wool. It is flexible, resistant to moth, oil and chemicals. The clothes made from acrylic are relatively cheap and are available in a variety of colours.

The full form of PVC is polyvinyl chloride. PVC is a thermoplastic. The plastics which gets deformed easily on heating and can be bent easily are called thermoplastics. It is used in the manufacturing of toys, combs and different types of containers.

The full form of PVC is polyvinyl chloride. PVC is a thermoplastic. The plastics which gets deformed easily on heating and can be bent easily are called thermoplastics.

Polythene is a thermoplastic. It is used in the manufacturing of toys, combs and different types of containers.

Frying pan handles are made with thermosetting plastics which are resistant to fire and can tolerate heat better than other plastics. For example, Bakelite is a thermosetting plastic which is a poor conductor of heat and electricity.

Synthetic fibers such as nylon or polyester are different from the natural fibers. They melt on heating. If the clothes made of synthetic fibers catch fire, it can be very dangerous. The fabric will melt and can stick to the body of the person wearing it. Hence, we should not wear synthetic clothes while working in a kitchen or working in a laboratory.

The raw materials for natural fibers are mainly derived from plants and animals. It requires the cutting of a lot of trees which leads to deforestation. On the other hand, the raw materials for synthetic fibers are mainly petrochemicals such as coal. Hence, the manufacturing of synthetic fibers helps in the conservation of forests.

PET is a form of polyester. Polyester is the synthetic fibre which is made up of repeating units of a chemical called an ester. Esters are the chemicals which give fruits their smell. PET is used for making bottles, utensils, films and wires.

Acrylic is a synthetic fibre which appears to resemble wool. It is flexible, resistant to moth, oil and chemicals.
It is used in the following ways:

• It is used for making sweaters and tracksuits and also for the linings of boots and gloves.
• It is also used in making furnishing fabrics and carpets.
• It can also be used to make fur and many different knitted clothes.

A synthetic fibre is made of small units which are joined together. These units are made of chemical substances. Such small units combine to form a large single unit called a polymer. Hence, a polymer is made of many repeating units. Polymers also occur in nature. For example, cotton is a natural polymer which is made from the cellulose. Cellulose is made up of a large number of glucose units.

Plastic is a polymer like a synthetic fibre. The arrangement of units in a plastic can be linear or cross-linked. The plastics which gets deformed easily on heating and can be bent easily are called thermoplastics. For example, polythene and PVC are thermoplastics. These are used in the manufacturing of toys, combs and different types of containers.

Some fibers are stronger than the others. The fibers are arranged in terms of strength in the following way:
Wool, Cotton, Polyester, Nylon, Silk.
Silk is the strongest fibre whereas wool is the weakest in terms of strength.

Synthetic fibers are different from the natural fibers. They melt on heating. If the clothes made of synthetic fibers catch fire, it can be very dangerous. The fabric will melt and can stick to the body of the person wearing it. Hence, we should not wear synthetic clothes while working in a kitchen or working in a laboratory.

Rayon can be used in the following ways:

• It can be mixed with cotton to make bed sheets.
• It can also be mixed with wool to make carpets.
• It is also used in textile industry to make textiles.