Density of a nucleus depends on the:

CONCEPT:

Atom: 

• An atom is composed of three particles, namely,  neutrons, protons, and electrons.
  • Hydrogen does not have neutrons.
  • Every atom has a nucleus that bounds one or more electrons around it. The nucleus is composed of protons and neutrons.
  • The protons are positively charged, electrons are negatively charged and neutrons are neutral.

Atomic mass: 

• It is the mass of an atom in a chemical element. It is roughly equivalent to total neutrons and protons present in the atom.
• It is expressed in atomic mass units (denoted by u). 1amu is equal to exactly one-twelfth of the mass of 1 atom of C-12.

CALCULATION:

• The relation between the density of a nucleus and the atomic number is given by

          ----(1)

⇒ R = R0A1/3         ----(2)

Where, ρ = density of nucleus, A = mass number, R = radius of the nucleus, and Ro = 1.2×10-15 m

From equation 1 and equation 2,

        ----(3)

• From equation 3 it is clear that the density of the nucleus is independent of atomic mass, mass number, and the number of neutrons.
• The density of a nucleus is constant for all the elements. Hence, option 4 is correct.