Question

Given below are two statements. One is labelled as
Assertion A and the other is labelled as Reason R.
Assertion A: Energy of $2s$ orbital of hydrogen atom is greater than that of $2s$ orbital of lithium.
Reason R : Energies of the orbitals in the same subshell decrease with increase in the atomic number
In the light of the above statements, choose the correct answer from the options given below.

Answer 1

As the atomic number increases then the potential energy of electrons present in same shell becomes more and more negative. And therefore total energy also becomes more negative.
$E_{total}=-13.6\frac{z^2}{n^2}eV$
$\therefore$ Energies of the orbitals in the same subshell
decreases with increase in atomic number.