Question

How do you calculate the number of neutrons present in the nucleus of an atom?

Answer 1

Hint: In order to calculate the number of neutrons present in the nucleus of an atom, we must be knowing about the concepts such as the atomic number and the mass number of the atom. From this we can easily calculate the neutrons present.

Complete step by step answer:
- First let us see what an atom is. All the matter is composed of tiny particles, which are called atoms. Atoms have many subatomic particles such as protons, neutrons, electrons, alpha and beta particles. An atom is made up of nucleus with the electrons revolving around it. The nucleus is composed of the protons and neutrons. The protons and neutrons together are called nucleons. Proton is one of the subatomic particles which has a positive charge. The neutron will be having a neutral charge. The electron will also have a charge which is negative.
- Let us first understand about the atomic number. The total number of the electrons or protons present in the atoms are called the atomic number, which is represented by the symbol Z.
- Now let us move onto the mass number. The total number of protons and neutrons together present in the nucleus of an atom will give the mass number, which is denoted by the symbol A.
- Now let us take an example of fluorine. The atomic number of Fluorine is 9 and the mass number of fluorine is 19.
- From the above given data, we can predict the number of neutrons present in the fluorine atoms.
The atomic number of fluorine is 9 which means the total number of electrons or protons present in the fluorine is 9.
- Now we can calculate the number of neutrons by subtracting the number of protons present in the fluorine, i.e. 9 from the mass number, i.e. 19.
Number of neutrons present in the nucleus of the Fluorine atom = 19 - 9 = 10.

Note: We have to remember that all protons, neutrons and electrons will be having different charges.
- The charge of the proton is positive.
- The charge of a neutron is neutral.
- The charge of the electron is negative.