An element's atomic number defines it. An element with 17 protons will always be chlorine. However an element's mass numbers can vary, which means that it can have different numbers of neutrons. So ...

Japanese scientists have made a new (nu?) periodic table organized by the number of protons in the nucleus instead of the element’s number of electrons. They call it the Nucletouch table, and where ...

Protons are tiny particles just a femtometer across, but without them, atoms wouldn't exist. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.