Question

Defend James Chadwick's work on the atom and its contribution to the modern atomic model.
plz help

Answer 1

Historically speaking, Chadwick and Rutherford were the first scientists who measured the nucleus radius, using the alpha-particles.
Furthermore, in the year of 193, the same Chadwick discovered a neutral particle, whose mass is approximately equal to the one of the proton. That particle was called neutron.

Answer 2

thankyou @Michele_Laino

Answer 3

oops.. the year is 1931
Thank you! @stephaniehoran23