(a) Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any similarly in the atoms of these elements ? (b) Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common ?

(a) Lithium, sodium, potassium are all metals that react with water to

1.	(a) Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any similarly in the atoms of these elements ? (b) Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common ?
Answer» Solution :a] Yes, the atoms of lithium, sodium, and potassium have one ELECTRON in their outermost shell. Hence, they show similar chemical properties. B] Both helium and neon are noble gases. The common THING between their atoms is that both have their outermost shell completely filled. Helium has 2 electrons in its outermost shell (K-shell) while neon has 8 electrons in its outermost shell (L-shell). Since their valence shell is completely filled, they are CHEMICALLY inactive.