Question

give the full ground state electron configuration for yttrium.

Explanation:

Step1: Determine yttrium's atomic number

Yttrium (Y) has an atomic number of 39.

Step2: Fill orbitals according to Aufbau principle

Start filling orbitals in order of increasing energy: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d.
1s can hold 2 electrons: $1s^{2}$
2s can hold 2 electrons: $2s^{2}$
2p can hold 6 electrons: $2p^{6}$
3s can hold 2 electrons: $3s^{2}$
3p can hold 6 electrons: $3p^{6}$
4s can hold 2 electrons: $4s^{2}$
3d can hold 10 electrons: $3d^{10}$
4p can hold 6 electrons: $4p^{6}$
5s can hold 2 electrons: $5s^{2}$
4d needs 1 electron to reach 39 electrons in total: $4d^{1}$

Answer:

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}5s^{2}4d^{1}$