QUESTION ABOUT QUANTUM NUMBERS

Question

what is the n, l, and ml value of the given orbitals below? (quantum numbers)

1. 3p
2. 5f
3. 4d

Answer 1

To follow up on the excellent description provided by @Nathan J, you can answer the question in the following way...

1. 3p n = 3; l = 1; ml = -1, 0, +1
2. 5f n = 5, l = 3; ml = -3, -2, -1, 0, +1, +2 + 3
3. 4d n = 4; l = 2, ml = -2, -1, 0, +1, +2

Answer 2

The principal quantum number, n, refers to the energy shell and will always equal the period number for an s orbital in the ground state. When you are told the orbital to assign quantum numbers to as is the case here, the principal quantum number will be the number that occurs before the letter. This is like the city part of an address.

The azimuthal, angular momentum, or orbital quantum number, l, currently takes values from 0 to 3 and increases by 1 in the sequence s->p->d->f with as yet undiscovered orbitals being assigned alphabetically after f. This is like the street number part of an address.

The magnetic quantum number, m_l, quantum number can take integer values between -l and l denoting which node an electron is in. This would be like an apartment number. Unless you get into advanced physical chemistry or quantum physics, this will mainly be used by teachers to increase the number of permutations of test banks in the form of a question such as "Which of the following quantum numbers could describe a 4p orbital?"

Finally, the spin quantum number, m_s, can take values of +/-0.5. You won't care which value you assign to the first electron except in specialized quantum physics experiments, but whenever you are putting in a second electron it should have opposite spin by the Pauli exclusion principal.