Question

The diameter of a chlorine atom is 200. pm. How many chlorine atoms are required to line up end to end to stretch a distance of 1.0 mm? Use 'E' for scientific notation.

Answer 1

The number of chlorine atoms needed would simply be the ratio of distance and diameter. But first convert 200 pm to mm:

200 pm = 2 E-7 mm             

So the number of chlorine atoms needed is:

1.0 mm / (2 E-7 mm) = 5,000,000 Chlorine atoms = 5 E6 atoms