Which best describes the effect of J. J. Thomson’s discovery? The accepted model of the atom was changed.
The accepted model of the atom was supported.
Cathode ray tubes were no longer used in experiments due to poor results.
Cathode ray tubes became the only instrument of use in the study of atoms.

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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i do not get it   at all