Periodic table

Periodic Table

A table that organizes elements into groups based on their properties, consisting of metals, metalloids, and non-metals.

Groups

Columns in the periodic table that contain elements with similar properties.

Periods

Rows in the periodic table that comprise elements with the same number of occupied energy levels.

Atomic Radius

The size of an atom, which increases down a group due to more occupied energy levels and decreases across a period due to increased effective nuclear charge.

Ionization Energy

The energy required to remove an electron from an atom; generally decreases down a group and increases across a period.

Electron Affinity

The amount of energy released when an electron is added to an atom; decreases down a group and increases across a period.

Electronegativity

A measure of the tendency of an atom to attract a bonding pair of electrons; decreases down a group and increases across a period.

Reactivity of Group 1 Elements

Increases with depth in the group when reacting with water.

Reactivity of Group 17 Elements

Decreases down the group when reacting with halide ions.

Oxidation States

A helpful tool for tracking electron distributions in substances; pure elements have an oxidation number of zero.

Metallic and Non-metallic Properties

Show a continuum from basic metal oxides to amphoteric to acidic non-metal oxides.