Fox was uncharacteristically quiet as he drove, and if it werenât for his occasional turning of the steering wheel, I would have thought someone had crafted a wax-statue of him and stuck it next to me. âThanks for driving me,â I finally said, just to say something.
Everything is made of atoms. An atom is the smallest particle of an element, like oxygen or hydrogen. Atoms join together to form molecules. A water molecule has three atoms: two hydrogen (H) atoms and one oxygen (O) atom. That's why water is sometimes referred to as H2O. A single drop of water contains billions of water molecules.
A molecule is the smallest particle of a substance that exists independently. Molecules of most elements are made up of only one of atom of that element. Oxygen, along with nitrogen, hydrogen, and chlorine are made up of two atoms. Look at the model of oxygen above. The two balls represents the two oxygen molecules.