We can tell when a chemical reaction occurs by looking at the result. If the matter changes identity rather
than just form, then a (4). has occurred.

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.

the answer is a! (2.9 x 10^-18 j) hope i could someone. : )