Question

(a) Lithium, sodium, potassium are all metals that react with waterto liberate hydrogen gas. Is there any similarity in the atoms ofthese elements?

(b) Helium is an unreactive gas and neon is a gas of extremely lowreactivity. What, if anything, do their atoms have in common?

Answer 1

(a) Yes. The atoms ofall the three elements lithium, sodium, and potassium have oneelectron in their outermost shells.

(b) Both helium (He) and neon (Ne) have filledoutermost shells. Helium has a duplet in its K shell, while neon hasan octet in its L shell.