Atomic Structure and Theory Vocabulary

Vocabulary terms and definitions covering atomic structure, models of the atom, and subatomic particles from the lecture notes.

Average Atomic Mass

The weighted average mass of all naturally occurring isotopes of an element.

Atomic Number

The number of protons in the nucleus of an atom, which identifies the element.

Bohr Model

A model of the atom where electrons travel in specific circular paths, or shells, around the nucleus.

Bright-Line Spectra

A series of specific wavelengths of light emitted by an element, used as a "fingerprint" for identification.

Electron

A subatomic particle with a negative charge and negligible mass, located outside the nucleus.

Electron Configuration

A notation that shows the distribution of electrons in an atom's energy levels.

Excited State

A condition where an electron has absorbed energy and jumped to a higher energy level.

Gold Foil Experiment

Rutherford’s experiment that led to the discovery of the dense, positively charged nucleus.

Ground State

The lowest energy state of an atom where electrons occupy the lowest available energy levels.

Isotope

Atoms of the same element that have the same number of protons but a different number of neutrons.

Mass Number

The total number of protons and neutrons in the nucleus of a specific atom.

Neutron

A subatomic particle with no charge and a mass of approximately $1\,\text{amu}$, located in the nucleus.

Nucleus

The dense, central core of an atom containing protons and neutrons.

Orbital

According to the Wave-Mechanical model, a region in an atom where there is a high probability of finding an electron.

Principal Energy Level ($n$)

The specific shell or layer where electrons are located.

Proton

A subatomic particle with a positive charge and a mass of approximately $1\,\text{amu}$, located in the nucleus.

Subatomic Particle

The fundamental components of an atom: protons, neutrons, and electrons.

Transition

The movement of an electron between different energy levels, which involves the absorption or emission of energy.

Wave-Mechanical Model

The current modern model of the atom that treats electrons as having both wave and particle properties.