What element only exists as a compound on Earth and is the fuel of stars???/?

Answer 1

It is hydrogen (H). Hydrogen must always exist as a compound, forming a covalent bond with another hydrogen atom (H2).

Atoms such as this are called 'diatomic'. There are others (N, O, F, Cl, Br, and I), however, only H is the stuff of the sun.

Use the extra info to dazzle your teacher.

. . . and if you didn't know, now you do . . .

Answer 2

Hydrogen