Question

the main difference between j.j. thomson and ernest rutherfords atomic models was a rutherfords model positioned the protons in a dense central area while thomsons electrons were scattered throughout the mass. b thomsons model positioned the protons in a dense central area while rutherfords electrons were scattered throughout the mass. c thomsons model placed the electrons in fixed orbits around the nucleus while rutherfords electrons were scattered throughout the mass. d rutherfords model placed the electrons in fixed orbits around the nucleus while thomsons electrons were scattered throughout the mass.

Explanation:

J.J. Thomson's plum - pudding model had electrons scattered throughout the mass. Rutherford's model had a dense central nucleus with electrons in orbits around it. Protons were not a part of Thomson's model. Rutherford's model placed protons in the nucleus.

Answer:

A. Rutherford's model positioned the protons in a dense central area while Thomson's electrons were scattered throughout the mass.