Match each vocabulary word with its definition. match the items in the left column to the items in the right column. 1. one mole of any gas at stp will occupy 22.4 l atomic mass 2. the sum of the protons and neutrons in an atom mole 3. 6.02 x 1023; the number of atoms, molecules, or particles in a mole mass number 4. atoms of the same element that have different numbers of neutrons avogadro's hypothesis 5. the relative mass of an atom as compared to the carbon-12 atom isotopes 6. the amount of a substance that contains the same number of atoms, molecules, or particles as 12 g of carbon-12 avogadro's number 7. the mass of an element or molecule in grams per mole (g/mol) molar mass

1. Avogadro's hypothesis. Avogadro hypothesized that equal volumes of all gases (at the same pressure) will have the same number of molecules. From PV=nRT, we know that one mole of gas takes up 22.4 L 2. Mass number. The mass number is the sum of the protons and neutrons in the nucleus so Carbon 12 has an atomic number of 6 which indicates 6 protons, and a mass number of 12 so 12-6 = 6 neutrons. 3. Avogadro's number. Avogadro's number is the number of units in one mole of any substance, which has been defined as 6.02 x10^23 4. Isotopes are the different forms of a single element. They differ in neutrons. One example is Hydrogen which has three isotopes Protium, Deuterium, and Tritium. 5. Atomic mass. The mass of the atom is equal to the sum of the protons and the neutrons as electrons are so small their mass is negligible. This is not exactly the same as the mass number because this number takes into account the different isotopes 6. mole A mole has the same number of entities as 12 grams of carbon 12, it is expressed by Avogadro's number so 1 mole = 6.02 x10^23 atoms or molecules, etc 7. molar mass - the amount that one mole of substance weighs. For carbon 12, 12 grams has one mole of atoms by definition. So for carbon 12, the molar mass is 12 g/mol