Which elements on the periodic table are highly reactive and which are inert?

In general, reactivity increases as you go down the periodic table for the the metals.

Inert elements are the group 18 elements (noble gases), because they have 8 valence electrons so they are already stable and don't need to combine with anything to increase their stability.

Highly reactive: Alkali Metals (increasing as you go down and the Halogens (decreasing as you go down).

Inert: Noble Gases.

Get an "A"

Alkali metals are very reactive, alkali-earth metals are a little less reactive, halogens are the most reactive gases.

theres a black zig-zag line, the non-metals are to the right of it