Atomic Structure and the Periodic Table

Vocabulary-style flashcards covering pure substances, materials properties, atomic structure, historical models, and periodic table organization based on lecture notes.

Pure substance

A substance that consists of only one type of particle.

Mixture

A combination of substances that are physically combined.

Element

A substance made of only one type of atom.

Compound

A substance where different atoms are chemically joined together.

Atom

The smallest unit of an element that retains its properties.

Malleable

A physical property describing a material's ability to be hammered into shape.

Conductive

A material's ability to carry electricity.

Lustrous

Having a shiny appearance.

Hardness

The resistance of a material to being scratched.

Metalloid

An element with properties intermediate between metals and non-metals, such as silicon or boron.

Alloy

A mixture of a metal with other metals and/or non-metals.

Stainless steel

An alloy of iron ($Fe$), chromium ($Cr$), and carbon ($C$) used for cutlery.

Brass

An alloy of copper ($Cu$) and zinc ($Zn$) used for instruments.

Bronze

An alloy of copper ($Cu$) and tin ($Sn$) used for statues.

Proton

A subatomic particle located in the nucleus with a charge of $+1$.

Neutron

A subatomic particle located in the nucleus with a charge of $0$.

Electron

A subatomic particle located in shells with a charge of $-1$.

Atomic number

The number of protons in an atom, which determines the element's identity.

Mass number ($A$)

The total number of protons ($p$) and neutrons ($n$) in an atom, calculated as $A = p + n$.

Neutron count ($n$)

Calculated by subtracting the proton number from the mass number: $n = A - p$.

Electron Shell Capacities

The first three shells in an atom can hold a maximum of $2$, $8$, and $8$ electrons respectively.

Democritus

The philosopher who first proposed the idea of atoms.

John Dalton

The scientist who proposed the solid sphere model of the atom.

J. J. Thomson

The scientist who proposed the plum pudding model of the atom.

Ernest Rutherford

The scientist credited with the discovery of the atom's nucleus.

Niels Bohr

The scientist who proposed that electrons exist in shells around the nucleus.

Dmitri Mendeleev

The scientist who organized the modern periodic table.

Group

A vertical column on the periodic table; elements within it share similar properties.

Period

A horizontal row on the periodic table.

Alkali Metals

The name given to elements found in Group 1.

Alkaline Earth Metals

The name given to elements found in Group 2.

Halogens

The name given to elements found in Group 17.

Noble Gases

The name given to elements found in Group 18.

Law of Triads

Early organization of elements into groups of three with similar properties.

Law of Octaves

The observation that every eighth element displays similar properties.