2025 · Q110
Number of electrons present in the species H, He, H2 and O2+ respectively are:
General KnowledgeChemistry
- A1, 2, 2, 15
- B1, 2, 1, 14
- C2, 2, 2, 16
- D0, 2, 1, 14
Explanation
Counting electrons: H has 1, He has 2, H2 has 2, and O2+ has 16 - 1 = 15 (the neutral O2 molecule has 16 electrons, and the +1 charge means one electron is removed). The sequence is therefore 1, 2, 2, 15. Counting once more confirms the sequence 1, 2, 2 and 15, matching option (a).