Neutrinos and antineutrinos are elementary particles with small but unknown mass. High-precision atomic mass measurements have revealed that beta decay of the silver-110 isomer has a strong potential ...

For example, a helium atom has an atomic mass of 4, but an atomic number (or ... Chadwick kept the problem in the back of his mind while working on other things. Experiments in Europe caught ...

The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...