1. The problem statement, all variables and given/known data If the size of the nucleus ( in the range of 10-15m to 10-14m) is scaled up to the tip of a sharp pin, what roughly is the size of an atom ? Assume the tip of the pin to be in the range 10-5m to 10-4m 2. Relevant equations 3. The attempt at a solution It's scaled up by a factor of 1010 i.e from 10-15m to 10-5m. And we also know that an atom's diameter is of the range 10-10 m, and so 10-10*1010 is 1 m. So if the nucleus is blown up to the size of a pin's tip, the size of the atom will be 1m right? My textbook however says " Thus the nucleus of an atom is as small as the tip of a a sharp pin placed at the center of a sphere of radius 1 m. How is this ? The diameter of the sphere should be 1 m right? Where am i wrong in my logic?