Question

2 multiple answer 1 point which electron configurations below are stable? (multiple answer may apply; select all correct answers) 1s² 1s² 2s² 2p⁶ 3s² 3p¹ 1s² 2s² 2p⁶ 3s² 3p⁶ 1s² 2s²

Explanation:

Step1: Recall stability rules

Stable electron - configurations often follow noble - gas configurations or have completely filled sub - shells.

Step2: Analyze $1s^{2}$

The $1s$ sub - shell is completely filled with 2 electrons, so it is stable.

Step3: Analyze $1s^{2}2s^{2}2p^{6}3s^{2}3p^{1}$

The $3p$ sub - shell is not full (it can hold 6 electrons, but here it has 1), so it is not stable.

Step4: Analyze $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}$

This is the electron configuration of argon, a noble gas. Noble - gas configurations are very stable.

Step5: Analyze $1s^{2}2s^{2}$

The $2s$ sub - shell is completely filled, so it is stable.

Answer:

A. $1s^{2}$
C. $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}$
D. $1s^{2}2s^{2}$