Solution:The given statement is true.
Concept- Group 1 elements are highly reactive in nature. These elements are lithium, sodium , potassium, Rubidium and Cesium.
As metals like sodium and potassium are highly reactive, they react violently with water to produce hydrogen gas with huge amounts of energy. The amount of energy released is so high that these metals catch fire when they come in contact with moisture.
The reaction can be shown as-
Potassium reacts with water to form potassium hydroxide with the evolution of hydrogen.This reaction is highly exothermic. Thus, potassium reacts with cold water as-
Similarly, the reaction of sodium with cold water is shown as
Thus, the given statement is true.
Hence, the correct option is (1).