Question

objective 3: radiometric dating

1. what is radioactivity and why does it occur?
2. what is a half - life?
3. referring to isotopes, what is the parent? daughter?
4. how do scientist use the parent and daughter to find the age of a rock layer or fossil?
5. what is radiocarbon dating?
6. when asked to confirm the age of an object believed to be from medieval times, which type of dating should be used and why?
7. using the graph below, answer the following questions...

Explanation:

1. Radioactivity is the spontaneous emission of radiation from the nucleus of an atom. It occurs because the nucleus is unstable and seeks a more stable state by emitting particles or energy.
2. Half - life is the time required for half of the nuclei in a radioactive sample to decay.
3. In isotopes, the parent isotope is the original radioactive isotope, and the daughter isotope is the product formed after the decay of the parent.
4. Scientists measure the ratio of parent to daughter isotopes in a rock layer or fossil. Using the known half - life of the parent isotope, they can calculate the time elapsed since the rock or fossil formed.
5. Radiocarbon dating is a method that uses the decay of carbon - 14 (a radioactive isotope of carbon) to determine the age of organic materials.
6. For an object from medieval times, radiocarbon dating should be used because carbon - 14 is present in all living organisms, and its decay can be measured over time spans relevant to medieval artifacts (up to about 50,000 years). Since the object is likely organic in nature (e.g., wood, bone), radiocarbon dating is appropriate.
7. Since the graph is not provided, this part cannot be answered.

Answer:

1. Radioactivity is spontaneous nuclear radiation emission due to nucleus instability.
2. Time for half of radioactive nuclei to decay.
3. Parent is original radioactive isotope; daughter is decay product.
4. Measure parent - daughter ratio and use half - life to calculate age.
5. Method using carbon - 14 decay to date organic materials.
6. Radiocarbon dating as object is likely organic and within its dating range.
7. Cannot answer without graph.