What is the rule of thumb for the activity trends of metals and nonmetals? Explain and give examples.

This for metal ... the farther to the left the more reactive they are. Group 1 metals, which include sodium and potassium, are so highly reactive that they do not exist in nature by themselves

Thats non metals ... the farther to the right the more reactive they are * with the exception of group 18 * which are the noble gases and do not react at all. The most reactive are group 17, which include fluorine and chlorine. These non-metals, like group 1, rarely exist by themselves because of their high reactivity.