Question

A substance was burnt in the air. The white residue obtained was added to water. This solution turned red litmus to blue. State whether the substance is a metal or non-metal.

Answer 1

The following substance is a METAL.  

Metals are basic in nature. When the metals are burnt they release metallic oxides which are also basic in nature.  

Red Litmus paper turns blue when bases act on it.  

Answer 2

The substance burnt in air was Magnesium which produce Magnesium Oxide on burning.When added to water, Magnesium hydroxide is formed which is basic in nature, turns red litmus to blue.