Periodic Table

Periodic

Something that repeats in a regular pattern.

Periodic properties

Characteristics that exhibit regular patterns, such as reactivity, density, valence electrons, ionization energy, electronegativity, and charge.

Alkali Metals

Group 1 elements with a positive charge (+1), known for being soft and highly reactive in air and water (e.g., Li, Na, K).

Alkaline Earth Metals

Group 2 elements with a positive charge (+2), harder than alkali metals and less reactive (e.g., Mg, Ra, Ca).

Halogens

Group 17 elements with a negative charge (-1), the most reactive nonmetals, existing in all three states of matter and often colored gases (e.g., Cl, I, F).

Noble Gases

Group 18 elements with a charge of 0, typically inert and having a full outer electron shell (e.g., He, Xe, Ar).

Transition Metals

Elements in Groups 3-12 with a positive charge (+2-+3 average), known for slow reactivity and typically producing colored ions (e.g., Fe, Hg, Ti).

Rare Earth Metals

Elements in the bottom two rows (Lanthanide and Actinide series) with a positive charge (+2-+3 average), including the last natural element (U) (e.g., Pu, U).

Hydrogen

An element not in any group, with both positive and negative charges (+1, -1), having 1 valence electron and existing as a gas, not a metal.