Question

To get complete information about an electron in an atom the quantum numbers required are:

• A. $n,l,m$
• B. $n,l$
• C. $n,l,m,s$
• D. $n,l,s$

Answer 1

The correct option is C $n,l,m,s$

Quantum numbers designate specific shells, subshells, orbitals, and spins of electrons. This means that they describe completely the characteristics of an electron in an atom, i.e., they describe each unique solution to the Schrödinger equation, or the wave function, of electrons in an atom.

There are a total of four quantum numbers: the principal quantum number ($n$), the orbital angular momentum quantum number ($l$), the magnetic quantum number ($m$), and the electron spin quantum number ($s$).

The principal quantum number, $n$, describes the energy of an electron and the most probable distance of the electron from the nucleus. In other words, it refers to the size of the orbital and the energy level an electron is placed in.

The number of subshells, or $l$, describes the shape of the orbital. It can also be used to determine the number of angular nodes.

The magnetic quantum number, $m$, describes the energy levels in a subshell, and $s$ refers to the spin on the electron, which can either be up or down.

Hence, quantum numbers $n$, $l$, $m$, $s$ are required to know completely about the electron.