Trends in the Periodic Table

Groups Alkali metals – group 1 Alkaline Earth Metals – group 2 Transition Metals – groups 3-12 Halogens – group 17 Noble Gases – group 18

Alkali Metals Most Reactive elements in periodic table Reactivity increases as you move down the group (Lithium least reactive – Francium most reactive) Only have one valence electron HYDROGEN is not included in this group It is placed here because it only has valence electron as well

Alkaline Earth Metals Still very reactive metals but not as reactive as the alkali metals Have 2 valence electrons

Transition metals

Halogens Most reactive non metals in the periodic table Have 7 valence electrons

Noble Gases Have 8 valence electrons Except for Helium which only has 2 Helium is still a noble gas because it has a full valence shell Considered non reactive