Rutherford's model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. ... It was after this that Rutherford began developing his model of the atom.
Answer:
Give any two application for isotopes
Isotopes of iodine are used for radiotherapy in treatment of hyperthyroidism, cancer, etc.
Uranium, Radium, Polonium isotopes are used in atomic reactors.
Cobalt isotopes are used for irradiation of food products.
Density is the measure of a mass per unit volume of a material substance
density= Mass/volume
The unit of density is g/cm^3