Molecules are connections or bonds between atoms. Atoms are the microscopic building blocks of the universe. They make up almost ANY material including solids, liquids, and gases! A human has more than 1 billion atoms! Atoms have specific parts. There is the nucleus, which is the center of the atom. Then, there are even smaller parts. They are protons, neutrons, and electrons! Molecules make up every element of the Periodic Table of Elements! Molecules can have lots of atoms! A simple molecule is O2 or Oxygen! That is two Oxygen bonded together! Water, or H2O has two Hydrogen atoms and one Oxygen atom! These atom bonds make everything that is in our universe. Without molecules, the universe would be nothing!