What best explains the formula unit for a compound made from nitrogen and hydrogen?

NH4, because nitrogen needs four electrons, and each hydrogen needs one electron.

NH4, because nitrogen needs one electron, and each hydrogen needs four electrons.

NH3, because nitrogen forms a single bond with each hydrogen atom.

NH3, because nitrogen forms a triple bond with each hydrogen atom.

Answer;

NH3, because nitrogen forms a single bond with each hydrogen atom.

Explanation; Nitrogen and hydrogen are both non-metals. An atom of nitrogen has 5 electrons in its outer shell, while that of hydrogen has 1 electron in its outer shell. Three hydrogen atoms each share their 1 electron with nitrogen to form three covalent bonds and make an ammonia molecule (NH3) Therefore; NH3 has a covalent single bond among its nitrogen and hydrogen atoms. A covalent bond means the N and H atoms share valence electrons