Describe how experimental evidence led each of the following scientists: Dalton, Rutherford, Thompson, Chadwick and Bohr, to develop increasingly more accurate models of the atom. You may use outside resources to supplement your essay.

Dalton:

Rutherford:

Thompson:

Chadwick:

Bohr:

Dalton Found out there was a small, hard indestructible sphere that is the smalles part of an element. He created his own Atomic Theory:

-All Matter is made up of small particles called atoms.

-Atoms cannot be created, destroyed, or divided into smaller particles.

-All atoms of the same element are identical in mass and size. The atoms of one element are different in mass and size from the atoms of other elements.

-Compounds are created when atoms of different elements link together in definite proportions.

Rutherford had found the positively charged nucleus in the middle of every atom using his Gold Foil Experiment. While doing this experiment, he expected these particles to just pass right through the foil but they bounced right back. He also proposed there were negatively charged electrons revolving around the nucleus.

Thompson found negative electrons and inferred atoms also contain negative particles. He inferred there was a lump of positively charged material, with negative electrons throughout. He used the Raisins Bun Model to explain.

Chadwick proved that it consisted of a neutral particle with about the same mass as a proton "Neutron" is the name given to the particle

Bohr believed Rutherford's prediction was correct, but it wasn't complete. Bohr proposed electrons could only move between energy levels, rather then being able to move everywhere.