Electron capture occurs more often than positron emission in heavy elements.
Heavy elements exhibit radioactivity.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false

Answer

B

Explanation

Electron capture occurs more often than positron emission in heavy elements. This is because if positron emission is energetically allowed, electron capture is necessarily allowed, but the reverse is not true, i.e., when electron capture is energetically allowed, positron emission is not necessarily allowed