In vulcanisation, natural rubber is heated with _____.

1. 1. Sulphur
   2. Carbon
   3. Silicon
   4. Phosphorus

Which one of the following does not wet the walls of the glass vessel in which it is kept?

1. 1. Water
   2. Mercury
   3. Alcohol
   4. None of the above

Dialysis is used for people with defective kidneys. It involves the process of _____.

1. 1. Osmosis
   2. Diffusion
   3. Adsorption
   4. Electropheresis

Which of the following is the lightest gas?

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

The substance coated on plastic tape-recorder tapes is _____.

1. 1. Zinc oxide
   2. Iron sulphate
   3. Iron oxide
   4. Manganese oxide

Which form of phosphorus is used in safety matches?

1. 1. White phosphorus
   2. Red phosphorus
   3. Yellow phosphorus
   4. Black phosphorus

In fireworks, the green flame is produced because of _____.

1. 1. Sodium
   2. Barium
   3. Mercury
   4. Potassium

Mixture of two metals is called _____.

1. 1. Alloy
   2. Mouse
   3. Hard Drive
   4. Dispersion

Dynamite was discovered by _____.

1. 1. Alfred Nobel
   2. Diamler
   3. Mosely
   4. Freud

Gypsum salt is _____.

1. 1. CaSO4, 2H2O
   2. CaSO4, H2O
   3. 2CaSO4, H2O
   4. CaSO4, 5H2O