Question

The _______________ react with the _______________ elements to form different compounds like lithium fluoride (LiF) and sodium chloride (NaCl). _______________ have a full valence level and do not combine with other elements.

Answer 1

Answer: Alkali metals, halogens, noble gases

Step-by-step explanation:

Ionic compounds are made of ions- charges. In LiF and NaCl, the first element has a +1 and the second element has a charge of -1. Elements that are +1 are alkali metals and elements that are -1 are halogens. Noble gases have full octets in their outermost valence shell, and since they're full it's so stable so it doesn't react with anything.