Periodic Table

Metals

Elements on the left/center of the periodic table; shiny, malleable, ductile, conduct heat/electricity; react with water (corrosion).

Non-metals

Elements on upper right; usually gas or dull solid; brittle if solid; do not conduct electricity; react with oxygen.

Metalloids

Elements along staircase between metals & non-metals; solids; can be shiny or dull; ductile and malleable; conduct heat/electricity moderately.

Period

Horizontal row of elements; elements differ from each other; numbered 1–7

Chemical Group/Family

Vertical column of elements; similar physical & chemical properties; numbered 1–18

Alkali Metals

Group 1, most reactive metals (except H), soft, shiny, react violently with water/oxygen, exist only as compounds.

Alkaline Earth Metals

Group 2, reactive metals (less than Group 1), shiny, form compounds.

Halogens

Group 17: most reactive non-metals, many can be poisonous (ex. chlorine gas in WWI)

Noble Gases

Group 18: colourless, odourless, tasteless; gases at room temp; glow with electricity; very stable, unreactive.

Transition Metals

Groups 3–12; solid at room temp (except Hg) silvery shine, malleable, good conductors.

Lanthanides (Rare Earth Metals)

Silvery/grey; very similar in appearance; conduct electricity well.

Actinides (Radioactive elements)

Most not found naturally; created in labs.