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 have one valence electron in their outermost shell, which is the electron they readily lose to form a +1 ion. This single outer electron sits in the highest energy level (the ns subshell), giving them the characteristic reactivity and chemistry of Group 1 elements. So the true statement is that there is one electron in the outer shell. The other options describe different groups: seven valence electrons would belong to halogens, eight would be a full outer shell like noble gases, and five doesn’t match the common valence of alkali metals.

Alkali metals have one valence electron in their outermost shell, which is the electron they readily lose to form a +1 ion. This single outer electron sits in the highest energy level (the ns subshell), giving them the characteristic reactivity and chemistry of Group 1 elements. So the true statement is that there is one electron in the outer shell. The other options describe different groups: seven valence electrons would belong to halogens, eight would be a full outer shell like noble gases, and five doesn’t match the common valence of alkali metals.