The mass of a copper atom is 1.06 10-25 kg, and the density of copper is 8 920 kg/m3 . (a) determine the number of atoms in 1 cm3 of copper.

Mass of copper atom is and density of copper atom is .

First calculate the volume from density and mass as follows:

Now, convert to ,

Thus,

Now,

Thus,

or,

m=8.92 g

The molar mass of copper is 63.54 g/mol thus, number of moles can be calculated as:

Now, in 1 mol of Cu there are atoms, number of atoms in 0.1403 mol will be:

double the distance = divide strength by 4