Question

Identify the element for each of these electron configurations. Then determine whether this configuration is the ground state or an excited state.

a. $1s^{2}2s^{2}2p^{5}3s$

b. $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^2$

Short answer

a. This configuration is for element Neon$\left(Ne\right)$.

b. This configuration is for element Titanium$\left(Ti\right)$.

Step-by-step solution

Part (a) step 1: Given Information

We need to find the configuration is the ground state or an excited state$1s^{2}2s^{2}2p^{5}3s$.

Part (a) step 2: Explanation

The electron configuration is:

$1s^{2}2s^{2}2p^{5}3s$

The electron configuration has $10$electrons so, $\left(Z=10\right)$and this configuration is for element Neon$\left(Ne\right)$.

Part (b) step 1: Given Information

We need to find the configuration is the ground state or an excited state

Part (b) step 2: Explanation

The electron configuration is:

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

The electron configuration has $22$electrons then,$\left(z=22\right)$ this configuration is for element Titanium$\left(Ti\right)$.