Which statement about the outer electrons of alkali metals is true?

Which statement about the outer electrons of alkali metals is true?

• A. One electron in the outermost shell
• B. Seven electrons in the outermost shell
• C. Eight electrons in the outermost shell
• D. Five electrons in the outermost shell

Answer: (A)

Alkali metals are in Group 1 and have one electron in their outermost shell. Their electron configuration ends with an s electron in the outer level (ns1), so they possess a single valence electron. That’s why they readily lose one electron to reach the stable arrangement of the nearest noble gas, forming +1 ions. The other options describe outer shells with seven, eight, or five electrons, which would correspond to different groups (halogens, noble gases, or other elements) and not to alkali metals. So having one electron in the outermost shell is the correct description.

Alkali metals are in Group 1 and have one electron in their outermost shell. Their electron configuration ends with an s electron in the outer level (ns1), so they possess a single valence electron. That’s why they readily lose one electron to reach the stable arrangement of the nearest noble gas, forming +1 ions. The other options describe outer shells with seven, eight, or five electrons, which would correspond to different groups (halogens, noble gases, or other elements) and not to alkali metals. So having one electron in the outermost shell is the correct description.