Answer: <u>An atom is the basic unit of matter</u> and the defining structure of elements. The difference between an atom and a molecule is that <u>molecules are formed when two or more atoms bond together</u>. If molecules contain atoms of different elements, that substance is known as a compound. <u>Atoms make up molecules. </u>
These segments have the following properties: 1. They are all parallel to each other. 2. They are all perpendicular to the axis of reflection. 3. They are all bisected by the axis of reflection.