How big are individual atoms? Atoms consist of a highly dense, positively charged nucleus and a surrounding electron cloud that is negatively charged. They are very tiny and can only be seen with a very advanced scanning tunneling microscope. Specifically, how big are individual atoms?
The size of the atom is approximately 10-10 meters, which is 0.00000000010 meters.
The mass of a single atom in kilograms is about 10-25 kg and the vast majority of its mass is made up of the nucleus (as much as 99.9%).