The scientist Neils Bohr improved Rutherford’s nuclear model. Bohr proposed a model that included a positively charged nucleus in the centre with electrons orbiting the nucleus in a similar way to how planets orbit the Sun.
Bohr’s model is called the planetary model.
The series of energy levels are at increasing distances from the nucleus. Each energy level holds a maximum number of electrons.
The idea that electrons orbit the nucleus was more accepted than a general cloud of electrons. This is because it supported the results of experiments by other scientists.
After more experiments, Ernest Rutherford confirmed that the positive charge in the nucleus is due to small particles, which we now know as protons.
Not long after, in 1932, James Chadwick provided evidence for particles in the nucleus with no charge. These are particles we now know as neutrons.
The discovery of the neutron allowed for a more improved model of the atom: