Understanding Atoms and Isotopes

A set of vocabulary flashcards covering fundamental concepts about atoms, subatomic particles, isotopes, and atomic masses.

Atomic Mass

The weighted average mass of the isotopes of an element.

Atom

The smallest particle of an element that retains the properties of that element.

Subatomic Particles

Particles smaller than an atom, including protons, neutrons, and electrons.

Proton

Positively charged particle located in the nucleus of an atom.

Neutron

Neutrally charged particle located in the nucleus of an atom.

Electron

Negatively charged particle that is found in space surrounding the nucleus of an atom.

Nucleus

The dense center of an atom containing protons and neutrons, positively charged.

Atomic Number

The number of protons in an atom, which also equals the number of electrons.

Isotope

Atoms with the same number of protons but different numbers of neutrons.

Mass Number

The sum of protons and neutrons in the nucleus of an atom.

Atomic Mass Unit (amu)

One-twelfth the mass of a carbon-12 atom.

Weighted Average Atomic Mass

Calculated based on the mass and percent abundance of each isotope of an element.

Isotope Notation

Representation of an isotope showing the element name followed by its mass number.

Percent Abundance

The relative percentage of a particular isotope in a natural sample.