A few years ago, he carried out the same experiment with muonic hydrogen, which contains only one proton in the nucleus and whose one electron was replaced by a negatively charged muon. The results ...

An atom is the smallest unit of an element that retains its chemical properties. It is made of protons, neutrons, and electrons. (Image: M ...

This image depicts the radium atom’s pear-shaped nucleus of protons and neutrons in the center, surrounded by a cloud of electrons (yellow), and an electron (yellow ball with arrow) that has a ...