Atomic Structure and Periodic Table Vocabulary

Vocabulary flashcards covering atomic structure, subatomic particles, isotopes, ions, electron shells, and periodic table organization.

Proton

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

Neutron

A subatomic particle located in the nucleus with a neutral charge ($0$) and a mass of $1\,\text{amu}$.

Electron

A subatomic particle located in the electron cloud with a negative charge ($-1$) and a mass of approximately $0\,\text{amu}$ (about $\frac{1}{2000}\,\text{amu}$).

Atomic Number

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

Mass Number

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

Average Atomic Mass

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

Isotopes

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

Radioactive Isotopes

Isotopes with unstable nuclei that break down or decay over time.

Valence Shell

The outermost electron shell of an atom.

Valence Electrons

The electrons located in the outermost electron shell that are involved in chemical bonding.

Bohr Model

A diagram showing the total number of protons and neutrons in the nucleus alongside the specific arrangement of electrons in each energy shell.

Lewis Dot Structure

A diagram showing an element's chemical symbol surrounded by dots representing its valence electrons.

Cation

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

Anion

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

Periodic Table Group

A vertical column on the periodic table containing elements that share the same number of valence electrons and similar chemical properties.

Periodic Table Period

A horizontal row of elements on the periodic table.

Periodic Table Square Components

A standard entry on the periodic table that displays an element's atomic number, chemical symbol, element name, and atomic mass.

Isotope Notation

A chemical notation displaying the element symbol, mass number as a top-left superscript, atomic number as a bottom-left subscript, and net charge as a top-right superscript.