Question

Which of the following has maximum atomic radius?
(A) Lu
(B) Yb
(C) Ce
(D) Eu​

Answer 1

Atomic radius of Europium is maximum i.e. 199pm.

Option (D) is correct.

Explanation:

When we move from left to right in the lanthanides series, the atomic size decreases due to lanthanide contraction.

• The atomic radius of Europium is 199pm.
• The atomic radius of the element Cerium (Ce) which lies on the left is about 183 pm.
• The atomic radius of the second last lanthanide Ytterbium (Yb) is 173 pm.
• The atomic radius of the Lutetium (Lu) is 173 pm.
• Thus atomic radius of Europium is maximum i.e. 199pm.