Question

Which pair of the following represents the same electron configuration?

a. [Ne] 3s₂ and 1s₂ 2s₂ 2p₆ 3s₂

b. [He] 3s₂ and 1s₂ 2s₂ 2p₆ 3s₂

c. [Ar]3s₂ and 1s₂ 2s₂ 2p₆ 3s₂

d. All represent the same configuration

Answer 1

Option a, [Ne] 3s₂ and 1s² 2s² 2p₆ 3s², represent the same electron configuration because [Ne] stands for 1s² 2s² 2p₆, so both notations simply detail the electrons beyond the neon core in the same fashion.

Step-by-step explanation:

The question is asking us to identify which pair represents the same electron configuration for an atom. The electron configuration is a representation of the arrangement of electrons around the nucleus of an atom, and noble gas notations are used to simplify the writing of electron configurations by representing the core electrons.

Let’s analyze each option:

• [Ne] 3s₂: This represents the electron configuration starting after neon (Ne) and includes two electrons in the 3s sublevel.
• 1s² 2s² 2p₆ 3s²: This is the full electron configuration including two electrons in the 1s sublevel, two in the 2s, six in the 2p, and two in the 3s.
• [He] 3s²: Incorrect because helium (He) goes only up to 1s², and doesn’t include the 2s and 2p electrons.
• [Ar]3s²: Incorrect because argon (Ar) is the noble gas for the 3p6 level, meaning that after argon, the electron configuration would start with 4s or 3d.

Therefore, the pair representing the same electron configuration is option a. [Ne] 3s₂ and 1s² 2s² 2p₆ 3s² are identical because [Ne] stands for 1s² 2s² 2p₆.