Atoms and Subatomic Particles

Vocabulary flashcards covering key concepts related to atoms and subatomic particles.

Atom

The smallest particle of an element.

Electron

A very small subatomic particle with a negative charge, located outside the nucleus of an atom.

Atomic Number

The number of protons in each atom of an element, which is unique to each element.

Neutral Atom

An atom that has an equal number of protons and electrons.

Negative Ion

An atom or molecule that has gained an electron, resulting in a net negative charge.

Electron Cloud Model

A model of the atom where electrons may be anywhere within the cloud around the nucleus.

Isotope

A variation of an element that has a certain number of neutrons in each atom.

Charge

An electrical property of matter that can be positive, negative, or neutral.

Element

A substance made up of only one type of atom.

Mass Number

The total number of protons and neutrons in an atom.

Neutron

A particle with zero net charge, located in the nucleus of an atom.

Planetary Model

A model of the atom in which electrons move in defined orbits around the nucleus.

Positive Ion

An atom or molecule with a net positive charge due to having more protons than electrons.

Net Charge

The overall electrical charge of a particle, calculated as the number of protons minus the number of electrons.

Nucleus

The central part of an atom, made up of positively charged protons and uncharged neutrons.

Radiation

Energy or particles released during radioactive decay.

Unstable Isotope

An isotope where the nucleus is likely to break apart and release radiation.

Stable Isotope

An isotope where the nucleus is not likely to break apart.

Subatomic Particle

A particle of matter that is smaller than an atom, including protons, neutrons, and electrons.

Radioactive Decay

The process of unstable atoms releasing radiation to achieve stability.