Question

What is the abbreviated electron configuration of Sn?

Answer 1

Tin -Sn on the periodic table is found in the fourteenth column of the periodic table Group IVB this is the second column of the p block. Tin is in the fifth energy level (row).
This means that Tin must end with an electron configuration of $5p^2$
The total electron configuration would be
$1s^{2}2s^{2}2P^{6}3s^{2}4s^{2}3d^{10}4p^{6}5s^{2}4d^{10}5p^2$
The noble gas Krypton has an electron configuration of
$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^6$

So we can replace this portion of tin's electron configuration with the noble gas notation [Kr]

This makes the electron configuration for Tin - Sn

$\left[Kr\right]5s^{2}4d^{10}5p^2$