Section 1
Models of the Atom
What evidence caused Thomson to change Dalton's solid sphere model into the plum pudding model?
What evidence caused Rutherford to change h omson’s plum pudding model into the nuclear model?
What evidence caused Bohr to change Rutherford’s nuclear model into the solar system model?
Positive and negative charges are attracted to one another. Which of the following are attracted to a negative charge: an electron, a proton, a neutron, a nucleus, an atom? Explain your thinking.
Hydrogen and helium are different elements. How can you use the plum pudding model to show how atoms of the two elements might be different from one another?
Suppose you discovered protons shortly after Thomson discovered electrons. How would you revise the plum pudding model to include protons? Draw a picture of your revised model of the atom.
Draw a solar system model showing one electron, one proton, and one neutron.
Use the Internet or another resource to find out how the size of an atom compares with the size of its nucleus. Is the diameter of an atom 10 times, $1,000$ times, or $100,000$ times the diameter of the nucleus?
The nuclear model and the solar system model both show atoms with electrons circling around the nucleus.a. How do these two models differ?b. How are these two models similar?c. How can you refine the solar system model so that the atoms do not look flat?
The ancient Greeks discarded the atomic theory because there was no evidence to support it. Try to provide evidence that atoms do indeed exist. Use the Internet to help you.
The ancient Greeks claimed that atoms were the smallest pieces of matter. Were they correct? Explain your thinking.
Give an example that shows how science is a process of gathering evidence and refining models.