Question

How sodium comes in contact with water?

Answer 1

Sodium gives out a vigorous reaction when comes in contact with humidity or water molecules. 

2Na + 2H2O  ---> 2NaOH  + H2

When sodium reacts with water, sodium hydroxide and hydrogen gas are formed, the reaction is highly exothermic. 

Answer 2

if we put sodium in water , it immediately reacts with water , as it is highly reactive and catches fire