Question

The quantum number of differentiating electron of copper atom in ${\text{4s}}$-orbital are:
$n = 4$, $l = 0$, $m = 0$ and $s = + 1{\text{/2}}$
A.True
B.False

Answer 1

A set of numbers which is used to describe the position and movement of an electron in an atom is known as quantum number. There are four quantum numbers namely, principal quantum number, azimuthal quantum number, magnetic quantum number and spin quantum number.

Complete step by step answer:
There are four types of quantum numbers:
Principal quantum number: Principal quantum number is designated by $n$. The principal quantum number designates the shell of the atom. Principal quantum number ranges from 1, 2, 3, 4,….
Azimuthal quantum number: Azimuthal quantum number is designated by $l$. The azimuthal quantum number designates the subshell of the atom. If $l = 0$ then it is s-subshell, if $l = 1$ then it is p-subshell, if $l = 2$ then it is d-subshell and if $l = 3$ then it is f-subshell.
Magnetic quantum number: Magnetic quantum number is designated by $m$. The magnetic quantum number designates the total number of orbitals in the subshell and their orientations. The values of magnetic quantum number range between $+ l$ to $- l$.
Spin quantum number: Spin quantum number is designated by $s$. The spin quantum number designates the spin of the atom. Its values are $+ {\text{1/2}}$ and $- {\text{1/2}}$.
Now, we are given a copper atom in ${\text{4s}}$-orbital. Thus,
The principal quantum number for a copper atom in ${\text{4s}}$-orbital is $n = 4$.
The azimuthal quantum number for a copper atom in ${\text{4s}}$-orbital is $l = 0$ because of s-subshell.
The magnetic quantum number ranges from $+ l$ to $- l$. Thus, the possible values of magnetic quantum number for a copper atom in ${\text{4s}}$-orbital is $m = 0$.
The spin quantum number for a copper atom in ${\text{4s}}$-orbital can be $+ {\text{1/2}}$ or $- {\text{1/2}}$.
Thus, the statement ‘quantum number of differentiating electron of copper atom in ${\text{4s}}$-orbital are:
$n = 4$, $l = 0$, $m = 0$ and $s = + 1{\text{/2}}$’ is true.
Thus, the correct option is option (A).

Note:
It is impossible for two electrons of the same atom to have the same set of quantum numbers. Thus, no two electrons can have the same set of quantum numbers.