Question

A gold atom has a radius of 145 pm. If you could string gold atoms like beads on a thread, how many atoms would you need to have a necklace 36 cm long?

Answer 1

First we have to convert:145 pm = 145 * 10^(-12) m36 cm = 360 mm = 360 * 10^(-3) mn = 360 * 10^(-3) m / 145 * 10^(-12) m = = 360 * 10^(-3) * 10^(12) / 145 = = 2.482758621 * 10^(9) or:2,482,758,621 atoms.