Enter the full electron configuration for S2�. What is the atomic symbol for the noble gas that also has this electron configuration?

1. Electronic configuration of sulphide ion S²¯ (18) => 1s² 2s²2p⁶ 3s²3p⁶

2. Ar

Explanation:

1. S²¯ simply indicates that the sulphur atom (S) has gained two extra electrons.

Thus we shall write electron configuration of sulphur (S) and sulphide ion (S²¯) as follow:

The electronic configuration of S²¯

S (16) => 1s² 2s²2p⁶ 3s²3p⁴

S²¯ (18) => 1s² 2s²2p⁶ 3s²3p⁶

2. Determination of the noble gas element that has the same electronic configuration as S²¯.

This is illustrated below:

Sulphur (S) has 16 electrons while the sulphide ion (S²¯) has extra 2 electrons making it to have a total electron of 18. Observing the elements in the periodic table, only Argon has 18 electrons with electronic configuration as:

Ar (18) => 1s² 2s²2p⁶ 3s²3p⁶

Therefore, sulphide ion (S²¯) has the same electronic configuration as Argon (Ar).