Question

What are nucleons?
A. the sum of protons and neutrons present in the nucleus
B. the number of protons in the nucleus
C. the number of neutrons present in the nucleus
D. the sum of protons, neutrons and electrons present in the nucleus

Answer 1

Hint: Atoms are made up of three fundamental particles, which differ in mass and electric charge are electrons, protons and neutrons. It is the smallest unit into which matter can be divided without the release of electrically charged particles.

Complete step by step answer:
Let us analyse the trend of electric charge and mass in these subatomic particles. The neutron and proton have approximately equal masses of 1 amu and the electron is about 1836 times lighter; its mass can sometimes be neglected as an approximation. The electron and proton have equal, but opposite electric charges; the neutron is not charged.
Out of the other atomic terms one of the terms is nucleons it is composed of subatomic particles in the nucleus of an atom that is protons and neutrons. Therefore nucleons are the sum of protons and neutrons present in the nucleus.

Hence the correct option is A.

Additional information:
protons and neutrons were discovered during carrying out of the electrical discharge in cathode ray tubes also known as canal rays. The smallest and lightest positive ion was obtained from hydrogen and was called protons. This positively charged particle was characterized in 1919.later a need was felt for the presence of electrically neutral particles as one of the constituents of atoms. These particles were discovered by Chadwick by bombarding a thin sheet of beryllium by alpha particles when electrically neutral particles having mass slightly greater than protons were emitted. He named these particles as neutrons.

Note:
Nuclide is another atomic term that describes various species of atoms in general. Sum of the number of protons and neutrons that is the total number of nucleons are termed the mass number of an atom denoted as A.