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 .