How many atoms are in a drop of mercury that has a diameter of 1.0 mm? (volume of a sphere is 4πr3/3; density of mercury = 13.6 g/cm3)?

The diameter of drop of mercury is 1.0 mm. The volume of drop is equal to the volume of sphere, thus, volume of mercury drop will be:

Here, r is radius of drop.

Radius of drop can be calculated as:

Convert the unit into cm

1 mm=0.1 cm

thus,

0.5 mm=0.05 cm

Volume of sphere will be:

Now, density of mercury is

Mass can be calculated as follows:

Molar mass of mercury is 200.59 g/mol thus, number of moles will be:

In 1 mole of a substance there are atoms thus, will have:

Therefore, number of atoms in a drop of mercury will be .