Synthetic fibres are man-made fibres. These fibres are made from petrochemicals. For manufacturing synthetic fibres cutting of trees or killing of animals is not required and we can conserve our natural environment using synthetic fibres. Hence, 'manufacturing synthetic fibres is actually helping coRead more
Synthetic fibres are man-made fibres. These fibres are made from petrochemicals. For manufacturing synthetic fibres cutting of trees or killing of animals is not required and we can conserve our natural environment using synthetic fibres.
Hence, ‘manufacturing synthetic fibres is actually helping conservation of forests’
Now a days, plastics become very important in our daily life, even though we should avoid them as far as possible as for the following reasons: • Plastics are non-biodegradable and take a lot of time to decompose. • Plastics are not eco-friendly. By burning plastics, poisonous fumes are released thaRead more
Now a days, plastics become very important in our daily life, even though we should avoid them as far as possible as for the following reasons:
• Plastics are non-biodegradable and take a lot of time to decompose.
• Plastics are not eco-friendly. By burning plastics, poisonous fumes are released that cause air pollution.
• Sometimes cows and other animals may eat plastics present in the garbage which may choke their respiratory system and even cause death.
• The plastic left in the soil results in soil pollution.
• Plastic bags drained into the water bodies cause threat to the aquatic life also.
• Polybags choke the drains and sewage pipes thus causing lot of trouble.
The bristles of a tooth brush should be made of soft material so that it does not harm the gums and the handle should be made of hard material so that it can give a firm grip. Therefore, the bristles are made up of nylon fibres which are strong, elastic, lustrous, light weight and easy to handle andRead more
The bristles of a tooth brush should be made of soft material so that it does not harm the gums and the handle should be made of hard material so that it can give a firm grip.
Therefore, the bristles are made up of nylon fibres which are strong, elastic, lustrous, light weight and easy to handle and the handle is made of hard plastic as it is strong, durable, poor conductor of heat and electricity.
We can store various kinds of chemicals and other materials in plastic containers because they are non-reactive and does not react with water and air. • Teflon, a kind of plastic is used as a coating to manufacture non-stick cookware. • Bakelite is a poor conductor of heat and electricity so it is uRead more
We can store various kinds of chemicals and other materials in plastic containers because they are non-reactive and does not react with water and air.
• Teflon, a kind of plastic is used as a coating to manufacture non-stick cookware.
• Bakelite is a poor conductor of heat and electricity so it is used for making electric switches and handles of the utensils.
• Melamine is used for making floor tiles and kitchenware.
Rana is advised to buy a cotton shirt for summers because cotton absorbs the sweat and the pores in cotton allows easy evaporation and keeps our body cool, whereas synthetic shirts don’t absorb sweat so, they are very uncomfortable to wear in summers. https://www.tiwariacademy.com/ncert-solutions/clRead more
Rana is advised to buy a cotton shirt for summers because cotton absorbs the sweat and the pores in cotton allows easy evaporation and keeps our body cool, whereas synthetic shirts don’t absorb sweat so, they are very uncomfortable to wear in summers.
‘Manufacturing synthetic fibres is actually helping conservation of forests’. Comment.
Synthetic fibres are man-made fibres. These fibres are made from petrochemicals. For manufacturing synthetic fibres cutting of trees or killing of animals is not required and we can conserve our natural environment using synthetic fibres. Hence, 'manufacturing synthetic fibres is actually helping coRead more
Synthetic fibres are man-made fibres. These fibres are made from petrochemicals. For manufacturing synthetic fibres cutting of trees or killing of animals is not required and we can conserve our natural environment using synthetic fibres.
Hence, ‘manufacturing synthetic fibres is actually helping conservation of forests’
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-3/
See less‘Avoid plastics as far as possible’. Comment on this advice.
Now a days, plastics become very important in our daily life, even though we should avoid them as far as possible as for the following reasons: • Plastics are non-biodegradable and take a lot of time to decompose. • Plastics are not eco-friendly. By burning plastics, poisonous fumes are released thaRead more
Now a days, plastics become very important in our daily life, even though we should avoid them as far as possible as for the following reasons:
• Plastics are non-biodegradable and take a lot of time to decompose.
• Plastics are not eco-friendly. By burning plastics, poisonous fumes are released that cause air pollution.
• Sometimes cows and other animals may eat plastics present in the garbage which may choke their respiratory system and even cause death.
• The plastic left in the soil results in soil pollution.
• Plastic bags drained into the water bodies cause threat to the aquatic life also.
• Polybags choke the drains and sewage pipes thus causing lot of trouble.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-3/
See lessShould the handle and bristles of a tooth brush be made of the same material? Explain your answer.
The bristles of a tooth brush should be made of soft material so that it does not harm the gums and the handle should be made of hard material so that it can give a firm grip. Therefore, the bristles are made up of nylon fibres which are strong, elastic, lustrous, light weight and easy to handle andRead more
The bristles of a tooth brush should be made of soft material so that it does not harm the gums and the handle should be made of hard material so that it can give a firm grip.
Therefore, the bristles are made up of nylon fibres which are strong, elastic, lustrous, light weight and easy to handle and the handle is made of hard plastic as it is strong, durable, poor conductor of heat and electricity.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-3/
See lessGive examples to show that plastics are noncorrosive in nature.
We can store various kinds of chemicals and other materials in plastic containers because they are non-reactive and does not react with water and air. • Teflon, a kind of plastic is used as a coating to manufacture non-stick cookware. • Bakelite is a poor conductor of heat and electricity so it is uRead more
We can store various kinds of chemicals and other materials in plastic containers because they are non-reactive and does not react with water and air.
See less• Teflon, a kind of plastic is used as a coating to manufacture non-stick cookware.
• Bakelite is a poor conductor of heat and electricity so it is used for making electric switches and handles of the utensils.
• Melamine is used for making floor tiles and kitchenware.
Rana wants to buy shirts for summer. Should he buy cotton shirts or shirts made from synthetic material? Advise Rana, giving your reason.
Rana is advised to buy a cotton shirt for summers because cotton absorbs the sweat and the pores in cotton allows easy evaporation and keeps our body cool, whereas synthetic shirts don’t absorb sweat so, they are very uncomfortable to wear in summers. https://www.tiwariacademy.com/ncert-solutions/clRead more
Rana is advised to buy a cotton shirt for summers because cotton absorbs the sweat and the pores in cotton allows easy evaporation and keeps our body cool, whereas synthetic shirts don’t absorb sweat so, they are very uncomfortable to wear in summers.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-3/
See less