Question

does Mg can react with both steam and hot water

Answer 1

yes,
Mg react with cold water to form hydroxide which stick to metal in form of very thin layer. It stops further reaction hence reaction stops at this stage.
& with steam its reaction is different...Mg burn in the presence of steam & directly form oxide although oxide layer once formed on metal surface may prevent further reaction but it presumed that oxide layer also have some degree of porosity through which steam can pass and react with metal. 

Answer 2

Answer:

Magnesium (Mg) It reacts very slowly with hot water. It reacts with steam when being heated and gives hydrogen gas and metal oxide.