There are four quantum numbers in an electron that orbits the atom.n, the principal quantum number.l, the angular quantum number., the magnetic quantum number. , the spin quantum number.
n is a positive integer. The value of n indicates the main shell of the electron. The electron in question is in the 3s orbital. As a result, n = 3.
l is a non-negative integer. The value of l indicates the type of subshell ("orbital") of the electron. The types of subshells possible depends on the main shell. For example, both s and p orbitals exist in the second main shell. However, only the s orbital exists in the first main shell. The value of l ranges from 0 to n - 1.l = 0 indicates an s orbital.l = 1 indicates a p orbital.l = 2 indicates a d orbital.l = 3 indicates an f orbital.
The electron in question is in an s orbital. As a result, l = 0.
is an integer. The value of indicates the position of the electron within the subshell. The range of depends on the value of l. ranges from -l to l (that's -l, ..., -1, 0, 1, ... l). Accordingly, there are 2 l + 1 orbitals in a l subshell. l = 0 for this 3s electron. There's only one orbital in the 3s subshell. The only value possible for this electron is 0.
The value of is either - 1/2 or 1/2. It indicates the position of an electron within a single orbital. The value of does not depend on that of n, l, or . However, by the Pauli Exclusion Principle, at least one of the four numbers must differ for two electrons in the same atom. In case all three of n, l, and are the same, the two electrons must differ in . However, this question asks only for the number of one single electron. Thus, giving either - 1/2 or 1/2 shall work.Reference
Vitz et. al, "5.8 Quantum Numbers (Electronic)", ChemPRIME (Moore et al.), Chemistry Libretexts. 27 Oct 2017.
Answer is: 2,0,0,±1/2.
1) n = 1. The principal quantum number (n) is one of four quantum numbers which are assigned to each electron in an atom to describe that electron's state.
2) l = 0. The azimuthal quantum number is a quantum number for an atomic orbital that determines its orbital angular momentum and describes the shape of the orbital.
3) ml = 0. Magnetic quantum number specify orientation of electrons in magnetic field and number of electron states (orbitals) in subshells.
Magnetic quantum number (ml) specifies the orientation in space of an orbital of a given energy and shape . Magnetic quantum number divides the subshell into individual orbitals which hold the electrons, there are 2l+1 orbitals in each subshell.
4) The spin quantum number, ms, is the spin of the electron; ms = +1/2 or -1/2.
So, it has two protons and two electrons.
The electron distribution for two electrons is 1 s^2.
That means that both electrons are in the orbital 1 s when they are in ground-state (not excited).
So, the quantum numbers are:
n = 1
l (lower case L) = 0
ms = 0
s = -1/2 and 1/2
So these are the two set of quantum numbers:
(1, 0, 0, +1/2), and (1, 0, 0, -1/2)