History of the Atomic Theory!

He shot alpha rays at beryllium, which emitted a neutral radiation. He put some beryllium in a vaccuum chamber with polonium. That emitted alpha rays and when the beryllium is shot with alpha rays, beryllium emits the neutral rays. Chadwick put a target and when the alpha rays hit the target, it knocks the atoms out. he colllectd some of the atoms in a chmaber and when a charged particle went through the chamber it ionized the gas. After testing, the only explanatin for his results was a neutral particle