Question

a compound (a) which is black of a brown coloured element (X) obtained after it comes in contact with air.identify A and X and give chemical reaction​

Answer 1

The brown coloured metal is copper. Hence ′X′ is copper and the black coloured compound formed is Copper oxide.

Answer 2

Answer:

Explanation:

Black coloured element is Copper which when mixed with air forms Copper Oxide

A = Copper

X = Copper Oxide