1. Why do different isotopes of an element have the same chemical properties?

3. A mixture of two common isotopes of oxygen, oxygen-16 and oxygen-18, is put in a cylindrical chamber that is then spun around its long axis at a very high speed. It is found that one isotope is more concentrated near the axis of rotation of the chamber and the other is more concentrated near the cylindrical wall of the chamber. Why is that, and which isotope is located near the axis? near the wall?

5. Two nuclei have different mass numbers A1 and A2. Are the two nuclei necessarily isotopes of the same element? Explain.

7. What aspects of the composition of a nucleus can cause it to be unstable?

9. A nuclear explosion far out in space releases a large amount of alpha, beta, and gamma radiation. Which of these would be detected first by a radiation detector on Earth?

11. A standard treatment for some cancers inside the body is to use nuclear radiation to kill cancer cells. If the radiation has to pass through normal tissue before reaching the cancer, why would alpha radiation not be a good choice for such treatment?

13. Explain the concept of nuclear half-life.

17. One cause of uncertainty in carbon-14 dating is that the relative abundance of carbon-14 in atmospheric carbon dioxide is not always constant. If it is discovered that during some era in the past carbon-14 was more abundant than it is now, what effect would this have on the estimated ages of artifacts dated from that period?