Topic 3 Vocabulary

Front

Atom

Back

The smallest unit of a chemical element, consisting of a nucleus surrounded by electrons.

Front

Electron

Back

A subatomic particle with a negative charge, found in all atoms and acting as the primary carrier of electricity in solids.

Front

Nucleus

Back

The positively charged central core of an atom, containing most of its mass.

Front

Proton

Back

A subatomic particle found in the nucleus of every atom, with a positive electric charge.

Front

Neutron

Back

A subatomic particle found in the nucleus of atoms, with no electric charge.

Front

Atomic number

Back

The number of protons in the nucleus of an atom, determining the chemical properties of an element and its place in the periodic table.

Front

Isotope

Back

Variants of a particular chemical element that have the same number of protons but different numbers of neutrons.

Front

Mass number

Back

The total number of protons and neutrons in an atomic nucleus.

Front

Atomic mass

Back

The mass of an atom, typically expressed in atomic mass units.

Front

Periodic table

Back

A tabular arrangement of the chemical elements, organized by their atomic number, electron configuration, and recurring chemical properties.