Give the set of four quantum numbers that represent the indicated electron in each of the following elements. 
Mg (7th electron) 

• A. n = 2; l = 2; ml = 0; ms = +1/2
• B. n = 2; l = 1; ml = 0; ms = -1/2
• C. n = 2; l = 1; ml = +1; ms = +1/2
• D. n = 2; l = 1; ml = +1; ms = -1/2
• E. n = 2; l = 1; ml = -1; ms = +1/2

Answer: (C)

Verified step by step guidance

1. Understand the concept of quantum numbers: Quantum numbers are used to describe the properties of electrons in atoms. There are four quantum numbers: the principal quantum number (n), the azimuthal quantum number (l), the magnetic quantum number (ml), and the spin quantum number (ms).
2. Identify the electron configuration of magnesium (Mg): Magnesium has an atomic number of 12, meaning it has 12 electrons. The electron configuration is 1s² 2s² 2p⁶ 3s². The 7th electron is in the 2p orbital.
3. Determine the principal quantum number (n): The principal quantum number corresponds to the energy level of the electron. For the 7th electron in magnesium, n = 2, as it is in the second energy level.
4. Determine the azimuthal quantum number (l): The azimuthal quantum number corresponds to the subshell of the electron. For a p orbital, l = 1.
5. Determine the magnetic quantum number (ml) and spin quantum number (ms): The magnetic quantum number can have values from -l to +l. For the 2p orbital, ml can be -1, 0, or +1. The spin quantum number can be +1/2 or -1/2. The correct set for the 7th electron is n = 2, l = 1, ml = +1, ms = +1/2.