Question

How does the atomic number of an element identify it?

Answer 1

To determine what we can identify from the atomic number we should know what atomic number is. The number of protons represents the atomic number. Protons are present in the nucleus. The charge of the proton is $+ 1$. Every element has a fixed proton number.

Complete step-by-step answer: The atomic number is the number of protons present in the nucleus of an atom. Every atom has a unique atomic number.
The atomic representation is as follows:
$_{\text{Z}}^{\text{A}}{\text{X}}$
${\text{X}}$is the symbol of the atom.
${\text{Z}}$ is the atomic number of proton number.
${\text{A}}$is the atomic mass.
Every element has a fixed atomic number so, from the atomic number we can determine what element is.
For example consider Z = $1$, it means we have atomic number one. We know that the hydrogen element has only one proton so, Z = $1$ represents the hydrogen element.
Similarly, Z = $2$, it means we have atomic number two. We know that a helium element has two protons so, Z = $2$ represents the helium element.
Therefore, from the atomic number of an element we can identify it because the atomic number tells the number of protons.

Note: Atomic number combines with the number of neutrons to give the atomic mass of the atom. The charge of the nucleus is positive due to the charge of the proton. The charge of the nucleus is equal to the charge of the proton. From the help of atomic numbers we can identify the isotopes. The species having the same atomic number but different mass numbers are known as isotopes. $_{\text{1}}^{\text{1}}{\text{H}}$ , $_{\text{1}}^2{\text{H}}$ and $_{\text{1}}^2{\text{H}}$, all are isotopes of the hydrogen because all have the same atomic number so, represents the same element.