Question

The atom of an element is made up of $11$protons, $12$neutrons, and $11$electrons. What is its atomic number and mass number?

Answer 1

• The atomic number of an element is equal to the total number of protons present in the nucleus of the atom.
• $\mathrm{Atomic}\mathrm{number}=\mathrm{number}\mathrm{of}\mathrm{protons}$
• Since, the number of protons given is $11$, therefore, the atomic number of an element is$11$.
• The mass number of elements is equal to the sum of the total number of protons and neutrons present in the nucleus of the atom.
• $\mathrm{Mass}\mathrm{number}=\mathrm{Number}\mathrm{of}\mathrm{protons}+\mathrm{number}\mathrm{of}\mathrm{neutrons}$
• Mass number $=$$11+12=23$
• Hence, the mass number of elements is$23$.