Profit is producer surplus, minus fixed costs. In other words, its price minus variable costs. Profit, however, is price minus total cost. Since fixed cost is never negative, profit will always be less.
The atom is about 10-10 meters (or 10-8 centimeters) in size. This means a row of 108 (or 100,000,000) atoms would stretch a centimeter, about the size of your fingernail. Atoms of different elements are different sizes, but 10-10 m can be thought of as a rough value for any atom.
(How do atoms form?) What is the biggest atom? The smallest atom? If by biggest and smallest, you mean mass (which is a measure of how much matter is there), then the smallest is the hydrogen atom with one proton and one electron. Since electrons are about 2000 times less massive than protons (and neutrons), then the mass of an atom is mostly from the protons and neutrons.