Question

How many gold atoms would have to be lined up to span 4.5 mm ?

Answer 1

1×10⁻¹⁰m is an Angstrom and diameter of gold is 2.70 Angstroms
4.45 mm = 0.00445m
(2.7 x 10¹⁰) a = 4.45 x 10⁻³
a = (4.45 x 10⁻³) / (2.7 x 10⁻¹⁰)
=16481481.48 gold atoms