Which one of the following lanthanoids does not form ?
[ is lanthanoid metal ]
[ is lanthanoid metal ]
- (A)Pr
- (B)Dy
- (C)Yb✓ Correct
- (D)Nd
Answer: (C)
Solution
Forming needs the lanthanoid in the state, and among the lanthanoids that state is confined to cerium, praseodymium, neodymium, terbium and dysprosium.
Ytterbium is . After the two electrons and one electron are removed it is already at , and a fourth electron would have to be torn from the filled shell; the ionisation enthalpy demanded is far beyond what oxide formation can repay, so ytterbium is held to the and states.
Ytterbium therefore does not form .
Ytterbium is . After the two electrons and one electron are removed it is already at , and a fourth electron would have to be torn from the filled shell; the ionisation enthalpy demanded is far beyond what oxide formation can repay, so ytterbium is held to the and states.
Ytterbium therefore does not form .
JEE Main · 2021 · 26 Feb 2021 · Shift 1 · Single correct option