-particle

is: a helium nucleus with positive charge and relative atomic mass 4.0026.   [P8.1, P9.1, P9.2]

is ejected: in radioactive -decay.   [P9.2]

is denoted: or (or since it is a helium atom stripped of its two electrons).   [P8.1, P9.1, P9.2]

Copyright 1997, The Open University