With which of the following electronic configuration an atom has the lowest ionisation enthalpy?

1. A. 1s 2 2s 2 sp 3
2. B. 1s 2 2s 2 2p 5 3s 1
3. C. 1s 2 2s 2 2p 6
4. D. 1s 2 2s 2 2p 5

Attempt this NEET 2007 Chemistry question free — pick an option to reveal the correct answer and a step-by-step explanation. Then join NEET Mastery Quest to practise 15,000+ PYQ and 2027-syllabus questions.