The radius of a strontium atom is 215 pm. How many strontium atoms would have to be laid side by side to span a distance of 4.47 mm?

1 answer

A radius of 215 pm = diameter of 430 pm and that is 430E-12m.
The distance to be covered is 4.47mm or 4.47E-3m.
So 430E-12m x #atoms = 4.47E-3 m
Solve for # atoms.