Which of the following set of elements do not possess f -electrons?

Step-by-step solution

Electronic configurations of (i) Lanthanum (La) with (Z=57) is [ Xe ]₅₄ 5 d^1 6 s^2 (ii) Uranium (U) with (Z=92) is [ Rn ]₈₆ 5 f^3 6 d^1 7 s^2 (iii) Lawrencium ( Lr ) with (Z=103) is [ Rn ]₈₆ 5 f¹⁴ 6 d^1 7 s^2 (iv)Thorium (Th) with (Z=90) is [ Rn ]₈₆ 5 f^1 6 d^1 7 s^2 [ Rn ]₈₆ 6 d^2 7 s^2 (due to nearly same energy of 5 f and 6 d -orbitals). (v) Actinium (Ac) with (Z=89) is [ Rn ]₈₆ 6 d^1 7 s^2 (VI) Cerium (Ce) with (Z=58) is [ Xe ]₅₄ 4 f^1 5 d^1 6 s^2 On the basis of above given electronic configuration, elements