Test: Electronic Configuration of Elements (May 9) - NEET MCQ

Nuclear mass does not affect the valence shell because nucleus consists of protons and neutrons. Whereas proton, i.e. nuclear charge affects the valence shell but neutrons do not. Thus, option (c) is wrong.

Z = 12, 1s², 2s², 2p⁶, 3s² (n = 3)
Z = 17, 1s² 2s² 2p⁶ 3s² 3p⁵ (n = 3)

Z = 88, [Rn] 7s², hence belongs to group 2.

(A) 3d-transition series, Z = 21 (Sc) to Z=30 (Zn)
(B) Lanthanoid series, Z = 58 (Ce) to Z = 71 (Lu)
(C) Actinoid series, Z = 90 (Th) to Z = 103 (Lr)
(D) 4d-transition Z = 39 (Y) to Z = 48 (Cd) series,

Z = 79 [Xe]4f¹⁴5d^10.6s¹ (n = 6)
As n = 6, the element belongs to 6^th period.
Group = ns + (n - I)d, I + 10 = 11

Z = 3; 1s² 2s¹ ; Z = 20; 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

n = 4 hence, element lies in 4^th period.
Group number = ns + (n - 1)d = 2 + 8 =10

Barium belongs to s-block with an outer configuration 6s².

ns² np² are members of carbon family.
Chalcogens is the general name of 16^th group elements.

It belongs to p-block while other elements belong to d-block and same group.