Question

. Why is decomposition reactions called opposite of combination reactions? Write equations for these reactions.

Answer 1

in combination reaction two elements will combine to form a single compound
but in decomposition reaction a single compound splits into two elements

Answer 2

Decomposition is called the opposite of combination because in a decomposition reaction a single compound divides in 2 or more simpler compounds while in a combination reaction 2 or more reactants combine to give a single product. Also decomposition reactions are endothermic while combination reactions are exothermic