Using the periodic table predict which three elements will have similar chemical properties or reactivity

oxygen, sulfur and selenium as they are all in the same group of the periodic table - they are all chalcogens

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.