Question

Give the name of the particle which has $18$ electrons, $17$ neutrons and $17$ protons in it.

Answer 1

1. The atomic number is equal to the number of protons.
2. In the given particle, there are $17$ protons and hence the atomic number of the substance is $17$.
3. The particle having atomic number $17$ is chlorine $\left(\mathrm{Cl}\right)$.
4. $\left(\mathrm{Cl}\right)$ contains $17$electrons in a normal atom.
5. But in this case, there are $18$ electrons, which indicates that there's one electron more. Therefore, it is a chloride ion having a negative charge.

Hence, the correct answer is chloride ion $\left({\mathrm{Cl}}^{-}\right)$.