Atoms, Atomic Structure, and Molar Mass

Vocabulary flashcards covering the structure of the atom, subatomic particles, atomic numbers, isotopes, molar mass, and ion formation.

Subatomic Particles

The three constituent particles that make up an atom: protons, neutrons, and electrons.

Nucleus

The dense central region of an atom that contains protons and neutrons, which remains unchanged by ordinary chemical processes.

Electron Cloud

The region outside the nucleus of an atom where electrons are located.

Proton

A subatomic particle located in the nucleus with a relative charge of $1+$ ($+1.6022 \times 10^{-19}\,\text{C}$), an actual mass of $1.6726 \times 10^{-27}\,\text{kg}$ ($1.0073\,\text{amu}$), and a relative mass of $1$.

Neutron

A neutral subatomic particle located in the nucleus with a charge of $0$, an actual mass of $1.6749 \times 10^{-27}\,\text{kg}$ ($1.0087\,\text{amu}$), and a relative mass of $1$.

Electron

A subatomic particle located outside the nucleus with a relative charge of $1-$ ($-1.6022 \times 10^{-19}\,\text{C}$), an actual mass of $9.1094 \times 10^{-31}\,\text{kg}$ ($0.00054858\,\text{amu}$), and a relative mass of $0.0005$.

Atomic Number

The number of protons in the nucleus of an atom, serving as a unique identifier for an element and equaling the number of electrons in a neutral atom.

Mass Number

The total count of protons and neutrons in the nucleus of an atom ($\text{Mass Number} = \text{protons} + \text{neutrons}$).

Isotopes

Atoms of the same element that possess identical atomic numbers (same number of protons) but different mass numbers due to differing numbers of neutrons.

Atomic Weight

The weighted average of the atomic masses of all naturally occurring isotopes of an element, calculated as the sum of each isotope's mass multiplied by its fractional abundance.

Molar Mass

The mass of one mole of a substance expressed in units of grams per mole ($\text{g/mol}$), which shares the same numerical magnitude as the element's atomic mass in $\text{amu}$.

Avogadro's Number

The number of elementary entities (atoms or molecules) in one mole of a substance, specified in the lecture notes as $6 \times 10^{23}$.

Ion

A charged particle formed when a neutral atom either gains or loses electrons during chemical processes.

Cation

A positively charged ion formed when a neutral atom loses one or more electrons.

Anion

A negatively charged ion formed when a neutral atom gains one or more electrons.

Plum Pudding Model

An early historical atomic model associated with the discovery of the electron.

Planetary Model

A historical model of the atom associated with the discovery of the dense central nucleus.

Bohr Model

An atomic model representing the nucleus containing protons and neutrons surrounded by electrons residing in defined circular orbits.

J.Dalton

Had no subatomic particles

J. Thomson

Discovered electron

E. Rutherford

Found the Necules

N. Bohr

Fund protons and neutrons

E. Schrödinger

Found the electrons live in orbitals

Mass number

Protons + neutrons