In just the first 259 days of data collection, KATRIN, a beta-decay-based detector in Germany, has set the smallest upper ...

Physicists have set a new upper limit on the mass of neutrinos. And the finding could poke a big hole in the Standard Model ...

Since a nucleus contains protons and neutrons, most of the mass of an atom is concentrated in its nucleus.

All oxygen atoms have 8 protons and all sodium atoms have 11 protons. The nucleon number (or mass number) of an atom is the total number of protons and neutrons it contains. The nucleon number of ...

As they studied atomic disintegration, they kept seeing that the atomic number (number of protons in the nucleus, equivalent to the positive charge of the atom) was less than the atomic mass ...