Question

which groups of elements are never found as pure elements in nature? in other words, which elements are found in nature as part of a compound?

Explanation:

Alkali metals (Group 1) are highly reactive due to having one valence electron, which they readily lose. Halogens (Group 17 or 7A) are highly reactive non - metals as they need one electron to complete their valence shell. Both groups form compounds easily in nature.

Answer:

Alkali metals (Group 1) and halogens (Group 17 or 7A).