Democritus was the one who had theorized that atoms make up everything and they are indivisible.
Dalton was the creator of the first actual atomic theory, most of his research was on gasses and meteorology.
Thompson was the original man who put together the plum pudding model in which Rutherford later proved wrong during his career.
Rutherford had discovered the nucleus within an atom. He had put together gold foil experiment.
Bohr had developed the idea of neutrons and electrons surrounding the nucleus. He was also the creator of the planetary model we now use to calculate electrons with.
First, you need to know 1 kg = 10^3 g. And 1 m^3 = 10^6 m^3. So the 1 g/cm3 = 10^3 kg/m3. So the answer is 1.93*10^4 kg/m3.
The last set which is n=4 l=3 m=3 is a valid set
