Question

why are Reactants are gaseous but product is solid
​

Answer 1

+, used to separate one reactant or product from another. used to ... an alternative way of representing a substance in a gaseous state. ( s), indicates that the substance is in a solid state.

Answer 2

It is not that reactants are gaseous, reactant can be in any state it can be liquid, it can be an aquasolution it can be gases it is never that it is only in gaseous form and product can also be a gas or solid a liquid or an aqueous solution.