How can we use patterns on the periodic table to predict an element’s structure and reactivity?

Generally, it can be stated that for the elements on the left of the periodic table (first two groups) the reactivity of the elements increases as we go down a group.

Conversely, reactivity decreases down the group for elements in group 7.

It is also observed that the reactivity of the elements in the periodic table decreases from left to right, until group 6 is reached, after which it starts to increase once again, and then the reactivity becomes negligible when group 8 is reached.

Explanation: