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.

For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass, it seemed that something besides the protons in the nucleus ...

The atom is a complex system of particles. It's made up of a central nucleus consisting of protons and neutrons ... The forces that hold the helium-4 nucleus together are so strong that it's ...

The nucleus of each atom contains protons and neutrons. While the number of protons defines the element (e.g., hydrogen, carbon, etc.) and the sum of the protons and neutrons gives the atomic mass, ...

An alpha particle consists of two protons ... as a helium atom as it does not contain any electrons but it is written with the same chemical nomenclature as a helium atom: \(_{2}^{4}\ ...