Ernest Rutherford used the results from the particle scattering experiment to propose the nuclear model describing a central positively charged nucleus with orbiting electrons. Niels Bohr described that electrons were occupying energy shells in this way surrounding the nucleus. In 1932 James Chadwick discovered the neutron which suggested that the nucleus consists of protons and neutrons. These discoveries led to the theory of the nuclear model, which is the model of the atom we know today, nucleus containing protons and neutrons surrounded by electrons in energy shells.

In the nuclear model the nucleus containing protons and neutrons is surrounded by electrons in energy shells.

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Niels Bohr described that electrons were occupying energy shells in this way surrounding the nucleus.

shells around the nucleus

In 1932 James Chadwick discovered the neutron which suggested that the nucleus consists of protons and neutrons.

James Chadwick

Dalton first suggested the atom as the tiny particle making up an atom but suggested it couldn’t be divided any further. Thomson discovered the atom and theorised the plum pudding model where atoms are spheres of positive charge with negative charged electrons inside. Rutherford used the results from the particle scattering experiment to propose the nuclear model describing a central positively charged nucleus with orbiting electrons. Bohr described how electrons were occupying energy shells.

tiny sphere → plum pudding → particle scattering experiment → nuclear model

Mass in an atom is centralised in the nucleus.

nucleus