1. Pudding & Clouds Activity

2. Models of atoms
Scientists use pictures and models to represent atoms. A number of your drawings from last week look like the following. Each of drawings is a model of the atom.
1. Do you think you can see atoms? Why?
2. How do you think that scientists come up with drawings of atoms?
3. How do models help scientists and others out?

3. What’s a model and why do we need one for the atom?
1st: Atoms are extremely small and cannot be seen even with a microscope.
2nd: Because we can’t see atoms, we have to come up with a model to describe it.
3rd: A model is a simplified imitation of something you want to explain. For example, a map is a model of the earth.
4th: Models are very powerful in science because they are supported by scientific evidence that is accepted by the scientific community.

4. Pudding and Clouds Summary
Dalton
None – a solid sphere
Electrons – negative
Protons - positive
Thomson
Electrons – negative
Protons – positive
Nucleus of protons in center
Rutherford
Electrons – negative
Protons – positive
Nucleus of protons
Electrons orbit at different energy levels
Bohr
Electrons – negative
Protons – positive
Neutrons – neutral
Nucleus of protons and neutrons
Electrons in different energy level clouds
Quantum