Chem – Further Divisions of the Periodic Table


By far the most important division is the metals versus the non-metals, which we just talked about. However, some people also like to talk about how the periodic table is broken up into smaller divisions. The most common ones are alkali metals, alkaline earth metals, transition metals, metalloids, halogens, noble gasses, lanthanoids, and actinoids. This periodic table is very good at showing you where they are. The alkali metals are those in group number 1 from lithium down. Remember hydrogen is not a metal so it cannot be counted in that category. The alkaline earth metals follow group 2 from beryllium down. The transition metals include groups 3 through 12 starting with the column scandium and ending with the column of zinc. For the transition metals, some teachers will include elements beyond group 12 like tin and lead. Either way, they should make this clear, but many of them do not. The metalloids can also be a confusing category. They roughly run along the step-stair division between the metals and non-metals. They include B, Si, Ge, As, Sb, Te, and Po. Note that aluminum is not usually included in the metalloid category. The halogens are group 17, from fluorine down. The noble gasses are group 18, from helium down.


PRACTICE PROBLEMS: Name at least one element in that division or give the division that the element is in (Use the periodic table link in the text above to guide you).

Transition metals Cr, Mn, Fe, Co, Ni, Pt, Cu, Ag, Au, Zn…
Halogens F, Cl, Br, I, At, Uus
Alkali metals Li, Na, K, Rb, Cs, Fr
Alkali earth metals Barium
Transition metals Mercury
Noble gasses Neon


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