Help Determine the number of lead (Pb) atoms that could fit into a 3.0 L container if the density of lead is 11.34 g/cm3 Show work pls

Explanation: You know that the mass of an individual lead atom is equal to

3.4

⋅

10

−

22

grams.

A substance's density tells you what its mass per unit of volume is. In this case, you know that lead has a density of

11.3 g/cm

3

, which means that each

cm

3

of lead will have a mass of

11.3 g

.

Now, your cube has a volume of

2.00 cm

3

, which means that its mass will be equal to

2.00

cm

3

⋅

density



11.3 g

1

cm

3

=

22.6 g

Now all you have to do is look at the mass of one lead atom and figure out exactly how many lead atoms would be needed to make the total mass of the cube equal to

22.6 g

.

22.6

g

⋅

the mass per atom



1 lead atom

3.4

⋅

10

−

22

g

=

6.647

⋅

10

22

lead atoms

Rounded to two sig figs, the number of sig figs you have for the mass of an individual lead atom, the answer will be

no. of lead atoms

=

6.6

⋅

10

22

atoms

You can double-check this result by using lead's molar mass, which tells you what the exact mass of one mole of lead is.

22.6

g

⋅

1 mole Pb

207.2

g

=

0.1091 moles Pb

Now use Avogadro's number to determine how many atoms of lead you have in that many moles

0.1091

moles

⋅

6.022

⋅

10

23

atoms

1

mole

=

6.57

⋅

10

22

atoms

To two sig figs, you will once again get

no. of lead atoms

=