Scientists use the periodic table to quickly refer to information about an element, like atomic mass and chemical symbol. The periodic table’s arrangement also allows scientists to discern trends in ...

was less than the atomic mass (average mass of the atom). For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass ...

Fermi, among others, realized that nuclear fission was accompanied by the release of colossal amounts of energy from the conversion of mass into energy ... to develop an atomic bomb.