Atomic Theory and the Periodic Table

These flashcards cover key vocabulary terms and definitions related to atomic theory and the periodic table.

Atoms

Tiny, indivisible particles that make up matter, as proposed by Democritus.

Atomic Theory

Dalton's theory stating that each element is composed of atoms, which are indestructible and combine in whole-number ratios.

Plum Pudding Model

J.J. Thomson's model of an atom where negatively charged electrons are embedded in a positively charged sphere.

Nucleus

The positively charged center of an atom, containing protons and neutrons.

Neutron

A subatomic particle found in the nucleus of an atom, with no charge.

Coulomb's Law

States that the force between two charges increases with their size and decreases with distance.

The Strong Force

A fundamental force that overcomes the repulsion between positively charged protons in an atomic nucleus.

Atomic Number (Z)

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

Halogen

A group of nonmetals in Group 17 of the periodic table, known for their reactivity and tendency to form salts.

Noble Gas

An unreactive element in Group 18 of the periodic table that has a full outer electron shell.

Alkali Metals

Highly reactive metals in Group 1 of the periodic table, which have one valence electron.

Alkaline-Earth Metals

Elements in Group 2 of the periodic table that have two valence electrons and are slightly less reactive than alkali metals.

Transition Metals

Metals found in Groups 3-12 of the periodic table, known for their ability to use inner shells for bonding.

Lanthanides

Rare-earth elements ranging from atomic number 58 (cerium) to 71 (lutetium), similar in reactivity to alkaline-earth metals.

Actinides

Elements ranging from atomic number 90 (thorium) to 103 (lawrencium), known for their radioactivity.

Chemical Bonding

The process of atoms combining to achieve stable electron configurations, often involving gaining or losing electrons.