Multiple choice Which of the following species does Bohr’s theory apply to? H+ He+ Li+ Li2+ Be+ Be3+ Only 1 Both 1 and 2 1, 2 and 4 2, 4 and 6 3, 4 and 5 Reveal answer Fill a bubble to check yourself D Correct answer Explanation Bohr's theory is only applicable to single electron species like H atom. He+, Li2+ and Be3+ have single electrons, thus Bohr’ theory applies to them.