To convert from mass to moles, the molar mass must be used. This can be found on the Periodic Table.
Gold (Au): 196.96657 g/mol
Use this number as a ratio.
Multiply by the given number of grams.
Flip the fraction so the grams of gold will cancel.
The original measurement has 3 significant figures, so the answer must have the same. For the number we calculated that is the thousandth place. The 9 in the ten thousandth place tells us to round the 6 to a 7.
That's why rubbing your hands together makes them warmer. ... Friction causes the molecules on rubbing surfaces to move faster, so they have more energy. This gives them a higher temperature, and they feel warmer. Heat from friction can be useful.