If the diameter of a carbon atom is 0.15 nm, calculate the number of carbon atoms which can be placed side by side in a straight line across length of scale of length 20 cm long.

Question 2.35: If the diameter of a carbon atom is 0.15 nm, calculate the number of carbon atoms which can be placed side by side in a straight line across length of scale of length 20 cm long.
Answer
1 m = 100 cm
1 cm = 10^-2 m
Length of the scale = 20 cm
= 20 × 10^-2 m
Diameter of a carbon atom = 0.15 nm
= 0.15 × 10^-9 m
One carbon atom occupies 0.15 × 10^-9 m.
∴ Number of carbon atoms that can be placed in a straight line