Which best represents a reaction mechanism? A → A
A+B → reactants
A+B → products
A+A → A+A
To help others in the future

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.

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.