in the periodic table below, shade all the main - group elements for which the neutral atom has a half…

Explanation:

Step1: Recall s - subshell electron configuration

The s - subshell has a maximum of 2 electrons. A half - filled s - subshell has 1 electron, with the electron configuration of ns¹ (where n is the principal quantum number).

Step2: Identify main - group elements with ns¹ configuration

In the periodic table, the main - group elements are in groups 1, 2, and 13 - 18. The elements with a half - filled s - subshell among the main - group elements are those in group 1 (alkali metals). These elements have the general electron configuration of ns¹. The elements are H, Li, Na, K, Rb, Cs, Fr.

Answer:

Shade H, Li, Na, K, Rb, Cs, Fr.