(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

1 . Reaction of iron with steam : 

3Fe(s) + 4H₂O(g) → Fe₃O₄(aq)+ 4H₂ (g)                                                    

• Ferrous react with Steam to form iron / ferric oxide and liberates hydrogen gas .

2 . Reaction of clacium with water :

Ca(s) + H₂O(l) → Ca(OH)₂(aq) + H₂(g)

• Calcium reacts with water and produce Calcuim hydroxide and liberates Hydrogen gas .

3 . Reaction of Potassium with water :

2K (s) + 2H₂O(l) → 2KOH(aq) + H₂(g) + Heat

• Potassium reacts with water vigorously and produces Potassium hydroxide and hydrogen gas with large amount of heat .