Question

What electron could have quantum numbers, n = 4,

I = 2, mI = -2, ms = -1/2?

A.) A 4s electron

B.) A 4f electron

C.) A 4d electron

D.) A 4p electron

So I need help please and thank you! Apex

Answer 1

The answer above is correct: C. A 4d electron

Answer 2

Choice C.) A
`4\, \rm d` electron.

Step-by-step explanation:

In an atom, each electron has a unique set of four quantum numbers.

`n` is the principal quantum number. It gives the index of the energy shell that contains this electron. Hence, it must be a positive whole number (1, 2, 3, etc.) In this case,
`n = 4`. Hence, this electron is in the fourth main energy shell. Think about this number as giving the size of the orbital that holds this electron.

`l` is the orbital angular momentum quantum number. It gives the type (shape) of the orbital that holds this electron.
`l` should also be a whole number. However, unlike
`n`, the value of
`l` starts from
`0` and has an upper bound,
`(n - 1)`. Here are the meanings for some common values of
`l`:

• 
  `l = 0` corresponds to an s-orbital. (Requires
  `n \ge 1`.)
• 
  `l = 1` corresponds to a p-orbital. (Requires
  `n \ge 2`.)
• 
  `l = 2` corresponds to a d-orbital. (Requires
  `n \ge 3`.)

As a side note, in each energy level, each type of orbital can hold more than one electrons. The other two quantum numbers,
`m_l` and
`m_s`, help distinguish between these electrons. However, that's not very relevant to this problem.