Assign the position of the element having outẹr electronic configuration
i. 'n s^2 n p^4' for 'n=3'
ii. '(n-1) d^2 n s^2' for 'n=4', and
iii. '(n-2) f^7(n(-1)) d^1 n s^2' for 'n=6', in the periodic table.

Assing the position of the elements with outer electronic configuration (n-1) d^2 ns^2(n = 4)

Assing the position of the elements with outer electronic configuration (n-2)f7 (n-1)d^1 ns^2 (n=6)

General electric configuration of lanthanides is A. (n−2)f1−14(n−1)s2p6d0−1ns2 B. (n−2)f10−14(n−1)d0−1ns2 C. (n−2)f0−14(n−1)d10ns2 D. (n−2)d0−1(n−1)f0−14nsld General electronic configuration of lanthanides is[2002] a)(n – 2) f1 –14 (n –1) s2p6d0 – 1 ns2 b)(n – 2) f10 –14 (n –1) d0 – 1 ns2 c)(n – 2) f0 –14 (n –1) d10 ns2 d)(n – 2) d0 –1 (n –1) f1 – 14 ns2

Given that P(n, r)=n(n-1)(n-2) ….to r factors If P(n, 4) = 20 P(n, 2), find n

Which of the follawing transition will have minimum wavelength? n_4 rarr n_1 , n_2 rarr n_1 , n_4 rarr n_2 , n_3 rarr n_1

If the sum of the first n terms of an Arithmetic progression is S_n=nX+1/2n(n-1)Y where X and Y are constants, find S_1 and S_2 .

Find the sum of the series 1.n + 2 .(n-1) + 3.(n-2) + cdots + ( n-1) .2 + n.1.

if ^(2n+1)p_(n-1):^(2n-1)p_n=3:5 , prove that n = 4