Multiple choice In the following, the element with the highest ionisation energy is [Ne]3s2 3p3 [Ne]3s2 3p1 [Ne]3s2 3p4 [Ne]3s2 3p2 Reveal answer Fill a bubble to check yourself A Correct answer Explanation 15th group elements with half filled p - orbitals have high first ionisation potential. Half filled p-orbitals have a configuration of p3 Hence option 1 is chosen