Question

The element with the highest first ionization potential is:

• A. boron
• B. carbon
• C. nitrogen
• D. oxygen

Answer 1

Answer: (C)

nitrogen

Answer 2

The first ionisation increases from left to right in a period. But nitrogen has greater ionisation energy than oxygen. The reason is that the electronic configuration of nitrogen $(1{{s}^{2}}2{{s}^{2}}2{{p}^{3}})$ is stabler than that of oxygen. Hence, nitrogen requires more energy to loose an electron then oxygen.