(I) Reaction of iron with steam:
When red hot iron interacts with steam, formation of Iron (II, III) oxide and hydrogen takes place.
3Fe(s) + 4H2O(g) ⇾Fe3O4 (s)+ H2(g)
(II) Reaction f calcium with water:
Calcium reacts with cold water to form calcium hydroxide and hydrogen gas.
Ca(s) + 2H2O(l) ⇾Ca(OH)2(aq.) + H2(g)
(III) Reaction of potassium with water:
Potassium reacts violently with cold water to produce potassium hydroxide and hydrogen gas. During the process, much heat is generated and hydrogen rapidly burns.
2K(s) + 2H2O (l) ⇾2KOH (aq.) +H2 (g) + heat