Stains of rust from iron on clothes can be removed by _____.

1. 1. Petrol
   2. Oxalic acid
   3. Alcohol
   4. Hydrogen peroxide

Which of the following gases is used in fire extinguishers?

1. 1. Carbon dioxide
   2. Oxygen
   3. Hydrogen
   4. Nitrogen

Cooking gas is a mixture of two gases namely _____.

1. 1. Oxygen and Methane
   2. Oxygen and Nitrogen
   3. Bautane and Propane
   4. Methane and Carbon dioxide

Iron articles rust because of the formation of _____.

1. 1. ferrous chloride
   2. sodium carbonate
   3. a mixture of ferrous and ferric hydroxide
   4. ferric chloride

By which of the following gases is ripening of fruits hastened?

1. 1. Hydrogen
   2. Methane
   3. Ethylene
   4. Carbon dioxide

The energy emitted from the sun is supposed to be due to _____.

1. 1. Radioactive disintegration
   2. Combustion of hydrogen
   3. Nuclear fission
   4. Nuclear fusion

Oxidation involves _____.

1. 1. Combustion
   2. Gain of hydrogen
   3. Gain in electrons
   4. Loss of electrons

Atom bomb is based on the principle of _____.

1. 1. Nuclear fission
   2. Nuclear fusion
   3. Radioactive
   4. Both nuclear fission and fusion

The substances are radioactive which have _____.

1. 1. Electrons in their nuclei
   2. Nuclei with less number of neutrons
   3. Unstable nuclei
   4. Electrons removed from the outermost shell

On addition of salt to water, its _____.

1. 1. freezing point increases
   2. boiling point is not affected
   3. boiling point decreases
   4. boiling point increases