Physics 2000 Science Trek The Periodic Table

Alpha Particles

Alpha particles are fairly heavy, positively charged particles that some radioactive atoms commonly emit. We now know that an alpha particle is actually the nucleus of a helium atom, with two neutrons and two protons. One of Rutherford's recent experiments had convinced him that alpha particles and helium were the same thing, but "nucleus," "proton," and "neutron" meant nothing to him...yet.

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