Question

The metallic radius of a potassium atom is 231 pm. What is the volume of a potassium atom in cubic meters?

Answer 1

1 pm = 10∧-10 cm
Therefore, 230 pm is equivalent to 2.3 ×10∧-8 cm.
Atom is in the shape of a sphere,
The volume of a sphere is given by 4/3πr³
Thus, volume of the atom = 4/3π( 2.3 ×10∧-8)³
                                          = 4/3 (3.142 ×12.167×10∧-24
                                           = 5.096 ×10∧-23 cm³
but 1m³= 1000000cm³
Therefore, the volume of the atom = 5.096 ×10∧-29 m³