Question

(a) Name three elements that have a single electron in their outermost shells.
(b) Name two elements that have two electrons in their outermost shells.
(c) Name three elements with completely filled outermost shells.

Answer 1

(a) Lithium (Li), sodium (Na) and potassium (K) are three elements (metals of group 1) that have only a single electron in their outermost shell.

(b) Magnesium (Mg) and calcium (Ca) are two elements (metals of group 2) that have two electrons in their outermost shell.

(c) Helium (He), neon (Ne) and argon (Ar) are three elements (inert gases of group 18) that have a completely filled outermost shell.