Question

Why is the density of nucleus more than that of the atom?

Answer 1

Hint: The average nuclear density of any atom is about $2.304 \times {10^{17}}kg/{m^3}$ this value is invariant of the mass of an atom and hence is constant. Usually we know that about the electrons revolving around the nucleus so, the size of the nucleus is small as compared to size of the atom.

Complete answer: we know that nucleus consists of neutrons and protons. So, every element has a unique atomic number which is equal to the number of protons present in the nucleus. which leads to the fact that the mass of the nucleus will be different; it depends on the number of protons and neutrons in the nucleus. since different mass results in different density hence the nucleus of all elements does not have the same density. But we can write the average nuclear density of any atom is about $2.304 \times {10^{17}}kg/{m^3}$. Hence the density of nucleus more than that of the atom.

Additional information:
Most part of the atom is empty, the entire mass is concentrated at the centre of the atom which we called it as nucleus. Thus, mass per unit volume is nothing but density of the nucleus is more than that of the atom.
Nuclear density states that density of the nucleus of an atom, is the ratio of mass per unit volume inside the nucleus. Since the atomic nucleus carries most of the atom mass and the atomic nucleus is very small in comparison to the entire atom, the nuclear density is very high.

Note:
The term nuclear density is defined as the density of the nucleus of an atom. The nuclear density of a typical nucleus can be approximately calculated from the size of the nucleus. which we can tell by approximation based on the number of protons and neutrons present in the nucleus.