Quantum numbers can be thought of as labels for an electron. Every electron in a
ID: 479950 • Letter: Q
Question
Quantum numbers can be thought of as labels for an electron. Every electron in an atom has a unique set of four quantum numbers. The principal quantum number n corresponds to the shell in which the electron is located. Thus n can therefore be integer. For example, electron in the 2p subshell has a principal quantum of n = 2 because 2p is in the second shell. The azimuthal or angular momentum quantum number l corresponds to the subshell in which the electron is located. s sub shells are coded as 0, p subshells as 1, d as 2 and f as 3. For example, an electron in the 2p subshell has l = 1. As a rule, l can have integer values ranging from 0 to n - 1. The magnetic quantum number m_l corresponds to the orbital in which the electron is located instead of 2p_x, 2p_y and 2p_x, the three 2p orbitals can be labeled -1, 0, and 1, but not necessarily respectively. As a rule, m_l can have integer values ranging from -l to +l. The spin quantum number m corresponds to the spin of the in the orbital. A value of 1/2 means an "up" spin, whereas -1/2 means a "down" spin. Which of the following set of quantum numbers (ordered n, l, m_l, m) are possible for an electron in an atom? Check all that apply. 4, 3, -2, 1/2 4, 2, 3, -1/2 2, 1, 0, -1 3, 4, 0, 1/2 -1, 0, 0, -1/2 2, 1, -2, 1/2 3, 1, 0, -1/2 2, 1, 0, 1/2Explanation / Answer
Notation of set of quantum number = n, l, ml, ms
ms = spin quantum number
1) Principal quantum number never be negative.
Hence,
-1,0,0,-1/2 is not allowed.
2) Values of l = 0 to (n-1) . l always less than n.
Hence,
3,4,0,1/2 is not allowed.
3) Values of m = -l to +l . Hence, m is less than or equal to l.
Hence,
4,2,3,-1/2 is not allowed.
2,1,-2,1/2 is not allowed.
4) Spin quantum number = +1/2 or -1/2.
Hence,
2,1,0,-1 is allowed.
Therefore,
Allowabe set of quantum numbers are
4, 3, -2, 1/2 and 3,1,0, -1/2 and 2,1,0,-1/2