Answer:
Chadwick-he discovered the neutron. He discovered this by demonstrating a neutral particle with a mass the same as a proton through a reaction between gramma Ray's and a wax sample.
Rutherford-he discovered the concept of radioactive half-life, the radioactive element radon, and named alpha and beta radiation.
j.j.Thompson discovered that atoms where made up of smaller components. This had major effects for the field of physics.
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