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The four quantum numbers for the electron in the outer most orbital of potassium (atomic no. 19) are

1. n = 4, A = 0, m = 0, s = + 2 1
2. n = 4, A = 2, m = –1, s = + 2 1
3. n = 3, A = 0, m = 1, s = + 2 1
4. n = 2, A = 0, m = 0, s = + 2 1

Correct answer: n = 4, A = 0, m = 0, s = + 2 1

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