Name two metals which react violently with cold water. Write any four observations you would make when such a metal is dropped into water.

Explanation

i.Sodium and potassium are two metals which react violently with cold water.
ii. Observations:
a.When these metals are dropped in water, bubbles will be formed due to evolution of gas.
b.Heat is evolved in the reaction.
c. The evolved gas will catch fire.
d. The solution formed will be basic in nature and it will turn red litmus blue.