Thomson's plum pudding model of the atom was most directly replaced or refuted by a. Rutherford's discovery that atoms contain a nucleus
b. Chadwick's discovery of the neutron
c. Goldstein's discovery of protons
d. Democritus's idea that the atom is indivisible

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?