The Federal Communications Commission (FCC) is an independent agency of the United States government, created by Congressional statute (see 47 U.S.C. Â§ 151 and 47 U.S.C. Â§ 154) to regulate interstate communications by radio, television, wire, satellite, and cable in all 50 states, the District of Columbia and U.S. territories.
Water consists of H2O molecules that each conprise 3 atoms. A typical H2O molecule as a molecular weight of 18, disregarding isotopes. That means one mole weighs 18 grams. 1000 g / 18 g = 55.6 mole H2O in a liter of water. One mole is around 6 x 10^23 so around 3 x 55.6 x 6 or 1000 mole atoms. Wolfram|Alpha confirms: how many atoms are in a liter of water.
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.