# What is described as a nucleus of protons and neutrons surrounded by an electron cloud?

The ratio of the size of the nucleus to the electron cloud is $1 : 100 , 000$. An analogy that is often used is that if a pea were placed in the middle of a 100 yard football field, the pea would be the nucleus and the field would be the electron cloud. It's not a perfect analogy, but it does help to picture the size relationships between the nucleus and electron cloud of an atom.