From a love that's blind. You slip to the dark side. Across that line. On the dark side, oh yeah. On the dark side, oh yeah. The dark side's callin' now. Nothin' is real. She'll never know just how I feel. From out of the shadows. She walks like a dream. Makes me feel crazy.
Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, Î±. The symbol for the alpha particle is Î± or Î±2+. Because they are identical to helium nuclei, they are also sometimes written as He2+ or 4 2He2+ indicating a helium ion with a +2 charge. If the ion ...
Rutherford exposed very thin films of gold foil to radioactive isotopes that emitted alpha particles. Alpha particles are helium nuclei with two protons and two neutrons. (Rutherford didn't know that, but he knew alpha particles were heavy.) He set up detectors to detect alpha particles. He detected some alpha particles that had passed right through the gold foil. He also detected alpha particles that had rebounded right back at him. The passage of alpha particles through the gold foil proved that gold atoms were mostly empty space. The alpha particles that came back at him proved that a very dense nucleus in the center was bouncing them back. As Rutherford himseklf put it,