Atomic Structure and Subatomic Particles

Vocabulary flashcards defining an atom, the structure of its nucleus, and the properties of the three main subatomic particles.

Atom

The smallest particle of an element that still has the properties of that element.

Subatomic particles

The three main constituent particles that make up an atom: protons, neutrons, and electrons.

Proton

A subatomic particle found in the nucleus with a charge of $+1$ and a relative mass of $1$.

Neutron

A neutral subatomic particle found in the nucleus with a charge of $0$ and a relative mass of $1$.

Electron

A subatomic particle located outside the nucleus in electron shells with a charge of $-1$ and a very small relative mass ($\frac{1}{1840}$).

Nucleus

The region at the centre of the atom containing protons and neutrons, which has an overall positive charge.

Atomic number

Atomic number = number of protons