Question

2. Give scientific reasons.
a. All the mass of an atom is concentrated
in the nucleus.​

Answer 1

Answer:

All the mass of an atom is concentrated in the nucleus because atom contains three subatomic particles like electron, proton and neutrons.

Answer 2

you know, an atom contains mainly three subatomic particles ; electron, proton and neutron.

we also know, mass of electron is comparably negligible than mass of proton and that of neutron.

electron revolves around the nucleus in the orbit while proton and neutron are located at the centre of the atom, this centre is known as nucleus.

its means, mass of an atom = mass of protons + mass of neutrons

hence, mass of an atom is concentrated in the centre i.e., nucleus.

so we can say, all mass of an atom is concentrated in the nucleus