Question

Name three constituents of an atom and state mass and charge of each.

Answer 1

Hint: The constituents of an atom are electrons, neutrons and protons. The electron has a very small mass whereas neutron and proton are approximately 1800 times the mass of an electron.

Complete step by step answer
The constituents of an atom are electron, proton, and neutron. The proton and neutron exist inside the nucleus of an atom and electron generally remains outside the nucleus, attracted to the nucleus due to electrostatic forces.

The electron is a fundamental particle that cannot be further divided. It has a rest mass of $9.1 \times {10^ - }31Kg$ and a charge of $ - 1e$. This value in coulombs is $ - 1.6 \times {10^{ - 19}}C$.

The proton is a positively charged particle present inside the nucleus. Its charge is $ + 1.6 \times {10^{ - 19}}C$ and has a rest mass of $1.6726 \times {10^{ - 27}}\;Kg$.

The proton is about 1830 times heavier than the electron.

The neutron is the heaviest component of an atom. It has a total rest mass of $1.67493 \times {10^{ - 27}}Kg$. This is slightly higher than that of a proton. When a neutron undergoes $\beta $ decay, it splits into an electron and a proton. Thus, neutrons have to be heavier to conserve mass. Unlike the other two constituents, the neutron does not have a charge and can be said to have a charge of $0C$.

Additional information:
The nucleus of an atom is very dense. Positively charged protons are very tightly packed close to one another. The force that is capable of such strong attraction is called the strong nuclear force. This is much stronger than the electrostatic force between protons and acts on every nucleon independent of charge.

 Although electrons cannot be further divided, neutrons and protons have smaller sub-constituents called quarks. Each quark has a fractional charge of $ + \dfrac{q}{3}$ and they are held together by the exchange of theoretical particles called gluons.

Note: Since all of these particles travel at a very high seed, the relativistic effects alter the apparent mass of the particle. All masses mentioned are the rest mass ${m_0}$ of the particles and their mass while motion can be found as: $m = \dfrac{{{m_0}}}{{\sqrt {1 - \dfrac{{{v^2}}}{{{c^2}}}} }}$.