Which of the following is a clue of a chemical change?
a. balls of wax form when melted wax is poured into ice water
b. iron changes color when heated
c. gas bubbles form in boiling water
d. a gas forms when vinegar and baking soda are mixed?

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.