(40) GCSE Chemistry Revision "The Nuclear Model"

Nuclear Model

An atomic structure model where most of an atom is empty space, with a positive nucleus at the center containing most of the mass, and negative electrons surrounding it.

Alpha Scattering Experiment

An experiment that led to the replacement of the Plum Pudding model with the nuclear model of atomic structure.

Niels Bohr

A scientist who proposed that electrons orbit the nucleus at specific distances, known as energy levels or shells.

Proton

A tiny positive particle found in the nucleus; the number of protons determines the positive charge and type of element.

Neutron

A neutral particle discovered by James Chadwick, found in the nucleus alongside protons.

Relative Charge

The charge of one subatomic particle compared to another; protons are +1, neutrons are 0, electrons are -1.

Relative Mass

The mass of one subatomic particle compared to another; protons and neutrons have a relative mass of 1, while electrons have a much smaller mass.

Helium Atom

An example of an atom where the number of electrons equals the number of protons, resulting in no overall charge.

Atom Radius

Approximately 0.1 nanometers (1 × 10^-10 m), while the nucleus radius is about 1 × 10^-14 m.

Empty Space in Atoms

A characteristic of the nuclear model where most of the atom's volume is not occupied by particles.