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Which of the following is not permissible arrangement of electrons in an atom?
A
n = 3, l = 2, m = –2, s = $-\frac{1}{2}$
B
n = 4, l = 0, m = 0, s = $-\frac{1}{2}$
C
n = 5, l = 3, m = 0, s = $+\frac{1}{2}$
D
n = 3, l = 2, m = –3, s = $-\frac{1}{2}$
Detailed Solution
Rules: l can take values 0 to (n − 1); m can take values from −l to +l; s is $+\frac{1}{2}$ or $-\frac{1}{2}$.
n = 3, l = 2, m = –2: l = 2 is allowed for n = 3, and m = –2 lies within −2 to +2. Permissible.
n = 4, l = 0, m = 0: allowed (4s orbital). Permissible.
n = 5, l = 3, m = 0: l = 3 is allowed for n = 5, and m = 0 lies within −3 to +3. Permissible.
n = 3, l = 2, m = –3: for l = 2, m can only be −2, −1, 0, +1, +2; the value −3 is not possible.
Hence the arrangement n = 3, l = 2, m = –3, s = $-\frac{1}{2}$ is not permissible.
Note: the source prints the first and the fourth options identically; the first has been restored to m = –2, as in the original paper.
n = 3, l = 2, m = –2: l = 2 is allowed for n = 3, and m = –2 lies within −2 to +2. Permissible.
n = 4, l = 0, m = 0: allowed (4s orbital). Permissible.
n = 5, l = 3, m = 0: l = 3 is allowed for n = 5, and m = 0 lies within −3 to +3. Permissible.
n = 3, l = 2, m = –3: for l = 2, m can only be −2, −1, 0, +1, +2; the value −3 is not possible.
Hence the arrangement n = 3, l = 2, m = –3, s = $-\frac{1}{2}$ is not permissible.
Note: the source prints the first and the fourth options identically; the first has been restored to m = –2, as in the original paper.