Give word equations for the reactions of –

(a) Non-metals —

1. Sulphur
2. Carbon
3. Phosphorus

(b) Metals —

1. Sodium
2. Calcium
3. Magnesium

with oxygen.

Distinguish between Combustion and Respiration with suitable word equations only.

Give the main experimental points only to demonstrate that —

(a) magnesium

(b) candle

gains weight on burning.

Give reasons for the following:

(a) patients suffering from lung problems are kept in an oxygen tent.

(b) oxygen finds utility in welding & cutting of metals.