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Which one of the following sets of four quantum numbers represents the valence electron of a rubidium atom (Z = 37)?

1. 5, 0, +1/2
2. 5, 1, 0, +1/2
3. 5, 1, 1, +1/2
4. 5, 0, -1/2

Correct answer: 5, 0, +1/2

Solution

The correct option, 5, 0, +1/2, represents the valence electron of rubidium, which is in the fifth energy level (n=5), has an angular momentum quantum number (l) of 0 corresponding to an s orbital, and a spin quantum number of +1/2, indicating the electron's spin direction.

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