The standard enthalpy of formation of any element in its most stable state is zero.

Question

Quizplus · Accepted Answer

This is because the standard enthalpy of formation of a substance is defined as the change in enthalpy when one mole of the substance is formed from its constituent elements in their standard states, which have a standard enthalpy of formation of zero. Therefore, the enthalpy of formation of an element in its most stable state must also be zero.

The Standard Enthalpy of Formation of Any Element in Its