JEE Main levelSingle correct optionDifficulty 2 of 3df193
Match the elements in Column I with their ground-state outer configurations in Column II.
Column I: P = Th (Z = 90), Q = Pa (Z = 91), R = Am (Z = 95), S = Cm (Z = 96).
Column II: 1 = 5f77s2, 2 = 5f26d17s2, 3 = 6d27s2, 4 = 5f76d17s2.
AP-2, Q-3, R-1, S-4
BP-3, Q-2, R-1, S-4
CP-3, Q-2, R-4, S-1
DP-3, Q-1, R-2, S-4
Answer: B
Th is 6d27s2 (3). Pa is 5f26d17s2 (2). Am reaches the half-filled 5f7 with 7s2 (1). Cm retains 5f7 and adds a 6d electron, giving 5f76d17s2 (4). So P-3, Q-2, R-1, S-4.