A strand of human hair has a diameter of 72 μm72\ \mu\text{m}72 μm.
Estimate how many carbon atoms would fit in a single straight line across the diameter of this strand of hair.
In your calculation, use the typical radius of a carbon atom, which is approximately 7.5×10−11 m7.5 \times 10^{-11}\text{ m}7.5×10−11 m.
77 exam-style questions on OCR GCSE Chemistry Atomic structure. Each one has a worked solution and a mark scheme showing where the marks go.