Periodic Table

Metals

Elements that are shiny, malleable, ductile, good conductors of heat/electricity, and lose electrons to form cations.

Nonmetals

Elements that are dull, brittle, poor conductors of heat/electricity, and gain electrons to form anions.

Metalloids

Elements that have properties of both metals and nonmetals, and act as semiconductors.

Periodic Table Groups

Vertical columns that indicate elements with the same number of valence electrons and similar properties.

Alkali Metals

Group 1 elements that are very reactive.

Transition Metals

Groups 3–12; hard, shiny metals that are good conductors.

Halogens

Group 17 elements that are very reactive nonmetals.

Noble Gases

Group 18 elements that are unreactive and have a full valence shell.

Atomic Radius

The distance from the nucleus to the outermost electron; increases down a group and decreases across a period.

Ionization Energy

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

Electronegativity

The ability of an atom to attract electrons in a bond; increases across a period and decreases down a group.