Atoms combine to form molecules. There are only 115 distinct atoms, which combine to form a great variety of molecules. Give a few examples for each. A compound is made of two or more different elements which are chemically combined. A mixture is made of substances mixed together without chemically combining.
Examples are air, wine, and salt mixed with sand.
Give an example. No, usually not. For example, the chemical properties of water are very different from those of oxygen or hydrogen. Any process in which atoms combine to form compounds is a chemical reaction. Find the molecular mass of each of the following molecules.