Assertion (A) : When the transition element ionises, the `4s`-orbital electrons are removed before the `3d`-orbital electrons.
Reason (R ) : The energy of `3d`-orbital electrons is lower than that of `4s`-orbital electrons.

Options

A. Assertion is true but the Reason is false
B. Assertion is false, Reason is true
C. Both Assertion and Reason are true and the Reason is a correct explanation of the Reason.
D. Both Assertion and Reason are true but Reason is not a correct explanation of the assertion.

Answer

A

Explanation

It is true that 4s electrons ionises before 3d-orbital electrons but the energy level of 3d-orbital electron is more than 4s-orbital electrons.