The nucleus which is located at the heart of every atom makes up more than 99.9 per cent of its mass, but only a trillionth of its total volume.
At only 1/1,836th the size of a proton or neutron, electrons contribute almost nothing to an atom’s mass, but are the most active component of an atom, responsible for bonding.
More than 99.9 per cent of an atom’s volume is empty space. If an atom’s nucleus were the size of a basketball, its electrons would be zipping around several miles away.
When electrons jump between energy levels, they don’t move through the space between. Instead, they disappear from one level and then instantly reappear on another level.
Atomic nuclei are held together by the strong force, which is 1038 times stronger than gravity, but only operates on the minute scale of a nucleus.