Question

a Shiny brown coloured element x on heating becomes black name the element X and black coloured compound formed also explain the reaction type

Answer 1

X is copper (Cu) and the black coloured element fromed is copper oxide (CuO).

the equation of the reaction involve on heating copper is given below.

2Cu + O2 --- 2CuO

the reaction is combination reaction.

combination reaction: the reaction in which two or more substance to combine into one single substance.

Answer 2

Yea friend.. This is the NCERT QUESTION of Class X Science- 1st Chemistry lesson...

Copper is a shiny metal and it's colour is brown. When u heat it (adding Oxygen) it forms Copper oxide which is black in colour.

$cu + o{2} (2 \: is \: subscript) \: \: \: = \: \: \: cuo$
Hope it helps:)