Question

Write the electronic configuration of any one pair of isotopes and isobar?

Answer 1

Isotopes have the same number of protons in the nucleus or the same atomic number, but having different numbers of neutrons in the nucleus, or different mass number.
Carbon has the isotopes, ${}_6^{12}C$ and ${}_6^{14}C$. Being isotopes, they have the same electronic configuration as $(2,4)$.

Isobars differ in atomic number (or number of protons) but have the same mass number.
${}_{10}^{22}Ne$ and ${}_{11}^{22}Na$ are isobars. They have different electronic configurations as $2,8$ for ${}_{10}^{22}Ne$ and $2,8,1$ for ${}_{11}^{22}Na$.