Match the ions in Column I with their spin-only magnetic moments (BM) in Column II. Column I: P = U^3+ (5f^3), Q = Np^3+ (5f^4), R = Pu^3+ (5f^5), S = Cm^3+ (5f^7). Column II: 1 = 5.92, 2 = 7.94, 3 = 3.87, 4 = 4.9.

JEE Advanced levelSingle correct optionDifficulty 3 of 3df214

Match the ions in Column I with their spin-only magnetic moments (BM) in Column II. Column I: P = $U X^{3 +}$ ( $5 f^{3}$ ), Q = $Np X^{3 +}$ ( $5 f^{4}$ ), R = $Pu X^{3 +}$ ( $5 f^{5}$ ), S = $Cm X^{3 +}$ ( $5 f^{7}$ ). Column II: 1 = 5.92, 2 = 7.94, 3 = 3.87, 4 = 4.9.

Each ion has as many unpaired electrons as

5 f

electrons since n is at most 7: n = 3, 4, 5 and 7. Spin-only

n (n + 2)

gives 3.87, 4.9, 5.92 and 7.94 BM. So P-3, Q-4, R-1, S-2.