The picture shows a close-up of one carbon atom. A hydrogen atom has one proton as the nucleus and one electron in the region outside the nucleus. The electron and proton are attracted to each other.

But what makes up a carbon atom—or any other atom? The first subatomic particle to be identified was the electron, in 1898. Ten years later, the British physicist Ernest Rutherford discovered ...

The electron from each atom feels the attraction from the proton ... both directions and room for the electrons in the outer energy level of the atoms. The carbon atom and hydrogen atoms are close ...

Scientists have set up and observed a single electron bond between two carbon molecules. A traditional “single bond” is actually two electrons—one from each atom. This is one electron.