# What are the possible values of n and ml for an electron in a 5d orbital ? A) n = 5 and ml = -2, -1, 0, +1, or +2 B) n = 1, 2, 3, 4, or 5 and ml = 2 C) n = 5 and ml = 2 D) n = 1, 2, 3, 4, or 5 and ml = -2, -1, 0, +1, or +2

Apr 16, 2015

The answer is A).

The principal quantum number, or $n$, describes the energy lelvel in which the electron can be found, Since you're interested in an electron located in a 5d-orbital, $n = 5$.

The angular momentum quantum number, or $l$, describes the subshell, or orbital type, in which your electron is located. Since you have a d-orbital, $l = 2$.

The value of $l$ will give you the value of the magnetic quantum number, or ${m}_{l}$, which describes the orientation of the orbital.

The accepted values for ${m}_{l}$ range from $- l$ to $+ l$, which means that you can have 5 d-orbitals in the fifth energy level, ${d}_{x y}$, ${d}_{x z}$, ${d}_{y z}$, ${d}_{{z}^{2}}$, and ${d}_{{x}^{2} - {y}^{2}}$, each described by a magnetic quantum number

${m}_{l} = - 2$
${m}_{l} = - 1$
${m}_{l} = 0$
${m}_{l} = + 1$
${m}_{l} = + 2$

As an example, here's how these orbitals would look for the 3d subshell