http://www.ck12.org Chapter 2. Matter
- Carbon-14 slowly decays over time because it is radioactive. Why does the percent of carbon-14 remain the
same in living organisms? - How can the percent of carbon-14 in a dead organism be used to estimate the amount of time that has passed
since the organism died?
Review
- What are isotopes?
- Why do different isotopes of an element generally have the same physical and chemical properties?
- Describe the three isotopes of hydrogen.
- Relate the concepts of isotope and mass number.
- All oxygen atoms have eight protons, and most have eight neutrons as well. What is the mass number of an
oxygen isotope that has nine neutrons? What is the name of this isotope? - Why are many isotopes radioactive?