Answer:
- n = 3
-
= 1
= 1
Explanation:
Argon atom has atomic number 18. Then, it has 18 protons and 18 electrons.
To determine the quantum numbers you must do the electron configuration.
Aufbau's principle is a mnemonic rule to remember the rank of the orbitals in increasing order of energy.
The rank of energy is:
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s < 4f < 5d < 6p < 7s < 5f < 6d < 7d
You must fill the orbitals in order until you have 18 electrons:
- 1s² 2s² 2p⁶ 3s² 3p⁶ : 2 + 2 + 6 + 2 + 6 = 18 electrons.
The last electron is in the 3p orbital.
The quantum numbers associated with the 3p orbitals are:
- n = 3
- the fourth quantum number, the spin can be +1/2 or -1/2
Thus, the six possibilities for the last six electrons are:
- (3, 1, -1 +1/2)
- (3, 1, -1, -1/2)
- (3, 1, 0, +1/2)
- (3, 1, 0, -1/2)
- (3, 1, 1, +1/2)
- (3, 1, 1, -1/2)
Hence, the correct choice is:
- n = 3
-
