define mole . what are the 2 things that mole represents ?
Mole is the SI unit for amount of substance. It is used for the measurement of very small, microscopic particles such as atoms and molecules. Broadly speaking, it is used to measure the number of particles – whether atoms or molecules present in a given amount of substance. One mole is the amount of substance that contains as many particles as there are atoms present in exactly 12g of 12C isotope of Carbon. It has been found that there are 6.023 X 1023 atoms present in 12 g of 12C isotope of Carbon.
1 mole of Na atoms = molar mass of Na atoms = 23 g.
1 mole of H2O molecules = molar mass of H2O molecules = 18.02 g
Hence, mole represents the amount of substance and the number of particles in the substance.