Final answer:
The magnetic quantum number, ml, has allowable values from -l to +l and indicates the orientation of an orbital in space. The spin quantum number and the number of ml values being equal to n are both incorrect descriptions of the magnetic quantum number.
Step-by-step explanation:
The correct statements that describe the magnetic quantum number, denoted as ml, are:
- A. The allowed values for ml range from –l to +l including zero.
- B. This value indicates the orientation of an orbital in the space around the nucleus.
Statement C is incorrect because the magnetic quantum number is not known as the spin quantum number; that is the spin projection quantum number, denoted as ms, which can be +1/2 or -1/2.
Statement D is incorrect because the number of possible ml values is determined by the angular momentum quantum number l, and not the principal quantum number n. For a given l, there are 2l + 1 possible values of ml, which corresponds to the different orientations an orbital can have in space. To provide an example, if n = 2, l can be 0 or 1. If l = 1, the possible values for ml are -1, 0, and 1.