Roasting is the process in which the ore is heated in the presence of excess air.

Name the process . Ore heated in the absence of air .

An element occupies group number 15 and period number 2 reacts with hydrogen under high pressure and in the presence of a catalyst it terms a hydride (A). In presence of excess of air and in the presence of platinum it forms an oxyacid (B). Identify the element, A and B.

How to show that the presence of carbon-di-oxide in air?

Heat of fron differs from that of man by the presence of