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.
Water is what comes out of the tap, what comes down as rain, what flows in the rivers and in the oceans. In other words, it is a physical substance in your every day life. H2O is a symbol. It describes the abstract idea, that all physical substances are made up of (identical) molecules, and in turn each molecule is made up of different atoms. Now, according to this model, each water molecule consists of two Hydrogen atoms and one Oxygen atom. This is concisely written as H2O. In other words, the symbol describes the composition of a water molecule. Now, you can't SEE these molecules or atoms - they are WAY too small.