What best explains the formula unit for a compound made from fluorine and hydrogen? (5 points) a HF, because fluorine is short of one electron, and hydrogen is in excess of one electron. b HF, because both fluorine and hydrogen are capable of forming only one covalent bond. c H2F, because fluorine is short of two electrons, and hydrogen is short of one electron. d H2F, because fluorine is capable of forming one, and hydrogen is capable of forming two covalent bonds.