Question

When an atom bonds to another atom it is trying to fill its?

Answer 1

valence shell, which is the outermost occupied shell. By filling the valence shell, the atom becomes more stable. There are different ways that atoms can bond with one another: by sharing electrons (forming a covalent bond) or by donating or taking electrons (forming an ionic bond).

Answer 2

When an atom bonds to another atom it is trying to fill its outer shell