Thickness of strand hair = 50 μm
Diameter of an atom =
Now, with the help of conversion factors, convert thickness in micrometer into meter i.e. 1 micrometer =
So, thickness of strand hair =50 μm= 50 \times 10^{-6} m
Therefore,
number of atoms thick is a strand of hair =
=
Hence, number of atoms is thick is a strand of hair.