MolSynapsequestion bank

MolSynapse / Question bank / d- and f-Block Elements / Lanthanoids and lanthanoid contraction

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3df209

Which statements about ground-state atoms are correct?

ACe has the configuration $[Xe] 4 f^{1} 5 d^{1} 6 s^{2}$
BGd has the configuration $[Xe] 4 f^{7} 5 d^{1} 6 s^{2}$
CEu has the configuration $[Xe] 4 f^{6} 5 d^{1} 6 s^{2}$
DTb has the configuration $[Xe] 4 f^{8} 5 d^{1} 6 s^{2}$

Answer: A, B

Ce (

4 f^{1} 5 d^{1} 6 s^{2}

) and Gd (

4 f^{7} 5 d^{1} 6 s^{2}

, favoured by the half-filled

4 f^{7}

) are the first two. Eu is

4 f^{7} 6 s^{2}

(not

4 f^{6} 5 d^{1}

) and Tb is

4 f^{9} 6 s^{2}

(not

4 f^{8} 5 d^{1}

), so the last two statements are wrong.

Practice d- and f-Block Elements More on Lanthanoids and lanthanoid contraction

Previous questionNext question

More questions on Lanthanoids and lanthanoid contraction