Dalton’s Model Dalton thought that atoms were smooth, hard balls.

1. Introduction to Atoms Dalton’s Model Dalton thought that atoms were smooth, hard balls.

2. Introduction to Atoms Thomson’s Model Thomson suggested that atoms had negatively charged electrons set in a positive sphere. Each electron is represented by the symbol e−.

3. Introduction to Atoms Rutherford’s Gold Foil Experiment Rutherford was surprised that a few particles were deflected strongly. Which are the paths of the particles that were not predicted by Thomson’s atomic model?

4. Introduction to Atoms Rutherford’s Model According to Rutherford’s model, an atom was mostly open space. The “6+” in the model means that there are six protons in the nucleus.

5. Introduction to Atoms Bohr’s Model Niels Bohr suggested that electrons move in specific orbits around the nucleus of an atom.

6. Introduction to Atoms Cloud Model Electrons move rapidly in different directions around the nucleus.

7. Introduction to Atoms Modern Model of an Atom A carbon atom has a nucleus made up of positively charged protons and neutral neutrons. The nucleus is surrounded by a cloud of negatively charged electrons.

8. Introduction to Atoms Particles in an Atom An atom is made up of protons, neutrons, and electrons. What is the correct charge for each atomic particle?

9. Introduction to Atoms Isotopes of Carbon All isotopes of carbon contain 6 protons. They differ in the number of neutrons. What is the missing information for each isotope?