Multiple choice Which of the following isoelectronic species has more electrons than neutron? O2- F- Na+ Mg2+ Reveal answer Fill a bubble to check yourself A Correct answer Explanation Each ion has 10 electrons For F-, Z = 9 A = 19 n = 10 For Na+, Z = 11, A = 23, n = 12 For Mg2+, Z = 12 A = 24 n = 12 For O2-, Z = 8 A = 16 n = 8