Q1) Is pollution of air (due to burning of fuel) a slow or fast change?
Q2) Energy is needed for a change. Give two examples to support this statement.
Q3) Rahul puts a few drops of alcohol on the back of his hand, the alcohol disappears and the hand feels cold.Why does this happen?
Q4) Tearing of paper is said to be a change that cannot be reversed. What about paper recyling? Justify your answer.
Dear user,
1. Pollution of air is a slow change because burning of small amount of fuel or emission of smoke donot change the composition of air immediately.
2.To perform any change we require energy
Examples: a. To glow a bulb we require electric energy
b. To convert cold water into hot water we need thermal energy.
3. Alcohol is more volatile than water and evapoartion require heat energy which is derived from our hands and thus produces cooling effect.
kindly post your remainig queries in separate thread
Regards
1. Pollution of air is a slow change because burning of small amount of fuel or emission of smoke donot change the composition of air immediately.
2.To perform any change we require energy
Examples: a. To glow a bulb we require electric energy
b. To convert cold water into hot water we need thermal energy.
3. Alcohol is more volatile than water and evapoartion require heat energy which is derived from our hands and thus produces cooling effect.
kindly post your remainig queries in separate thread
Regards