The number of s-electrons present in an ion with 55 protons in its unipositive state is
- (A)8
- (B)9
- (C)12
- (D)10✓ Correct
Answer: (D)
Solution
An atom with protons is caesium, and removing one electron for the unipositive ion gives the closed xenon configuration . Counting the electrons in the sub-shells of this arrangement, the , , , and orbitals each hold two. Their sum is ten -electrons.
JEE Main · 2023 · 24 Jan 2023 · Shift 2 · Single correct option