Investigation 1: Atomic Structure Flashcards

Vocabulary flashcards defining fundamental chemical concepts, subatomic particles, atomic models, electron configurations, and states of matter based on the lecture notes.

Atom

The smallest unit of an element that retains the chemical properties of that element.

Proton ($p^+$)

A positively charged subatomic particle located in the nucleus of an atom with a mass of approximately $1\,\text{amu}$.

Neutron ($n^0$)

An uncharged subatomic particle located in the nucleus of an atom with a mass of approximately $1\,\text{amu}$.

Electron ($e^-$)

A negatively charged subatomic particle located in the electron cloud surrounding the nucleus with negligible mass.

Nucleus

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

Atomic Number

The number of protons in the nucleus of an atom, which uniquely determines the identity of an element.

Mass Number

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

Isotope

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

Ion

An atom or group of atoms with an overall electric charge resulting from the gain or loss of electrons.

Average Atomic Mass

The weighted average mass of all naturally occurring isotopes of an element, calculated from isotope masses and their percent abundances.

Energy Level

Specific quantized region surrounding an atomic nucleus where electrons reside.

Quantum

The discrete amount of energy required to move an electron from one energy level to another.

Atomic Emission Spectrum

The characteristic pattern of light frequencies emitted when excited electrons in an atom transition to lower energy levels.

Quantum Mechanical Model

The modern model of the atom that describes electrons using wave probabilities and three-dimensional orbitals rather than fixed paths.

Atomic Orbital

A three-dimensional region of space around the nucleus where there is a high probability of finding an electron.

Subshell

A subdivision of a principal energy level consisting of one or more orbitals with the same shape, designated as $s$, $p$, $d$, or $f$.

Electron Configuration

The arrangement and distribution of electrons among the various orbitals of an atom.

Valence Electrons

The electrons located in the outermost principal energy level of an atom that determine its chemical properties.

Electron Dot Structure

A representation of an atom's valence electrons using dots positioned around the element symbol.

Particle Organization in States of Matter

Solids consist of tightly packed ordered particles, liquids have close but fluid particles, and gases consist of widely spaced rapidly moving particles.

Structure of an Atom

A visual representation showing the central nucleus containing protons ($p^+$) and neutrons ($n^0$), surrounded by an electron cloud containing electrons ($e^-$).