Which term defines a type of oxygen that forms a protective layer miles above the earth a. fossil fuel b. smog c. pollution d. ozone

The correct and valid answer is, D. Ozone.

Ozone (The ozone layer) defines a type of oxygen that creates a protective layer miles abve the earth.

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.