1 pair of objects = 2 objects; 1 dozen of objects = 12 objects; 1 gross of objects = 144 objects

1 mole of objects = 6.022-10?3 objects (6.022-10?3 objects/mol - Avogadro's number).

It is determined by the number of carbon atoms in exactly 12 g of pure isotope C-12.

The molar mass is the mass of a mole of objects (g/mol). 1 amu = 1.66054-1024 g

1. a) A single oxygen-16 atom has a mass of 16.00 amu. Convert this mass to grams, and ther calculate the mass in grams of a mole of oxygen-16 atoms

b) Based on your results, identify the relationship between the numerical values of the mass of an atom in amu and the molar mass in g/mol.

2. Write the units that result from the following mathematical operations:

1 mole

Number of objects x reciprocal Avogadro's number: # of objects x6,022-1023 obiects : # moles

Moles Avogadro's number:

Mass reciprocal Molar Mass:

Moles x Molar Mass:

3. a) Calculate the number of atoms in 2 moles of helium.

b) Calculate the number of moles corresponding to 2.007-1023 atoms of helium

c) Calculate mass in grams of 2.5 moles of argon. The molar mass of argon 1s

d) Calculate the number of moles in 75 g of iron. The molar mass of iron 1s _g/mol

g/mol