"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Researchers just found out where the secret mass of protons is located. Physicists have long known that ...

Are the fundamental constants really constant? Recent investigations have shown that one essential fundamental constant -- namely the mass ratio of protons to electrons -- can have changed only by a ...

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.

Atoms are very small. They have a radius of around 1 × 10 10 metres. This symbol shows that chlorine has 35 particles in the nucleus (protons and neutrons), 17 of which are protons. It also tells us ...

The proton is slightly lighter than previously believed, according to the most accurate measurement so far of this particle’s mass. Protons weigh slightly more than one atomic mass unit (defined as ...