What is radioactivity?

What is radioactivity?

1. 1. What is an alpha particle? Write its symbol , including the atomic and mass numbers in the correct positions.

   • An alpha particle is a helium nucleus emitted by "some" radioactive substances, originally regarded as a 'ray'.

2. 2. What is a beta particle?Write its symbol , including the atomic and mass numbers in the correct positions.

   • A beta particle is a fast-moving electron emitted by radioactive decay of substances (originally regarded as rays).

3. 3. Give the names of four radioisotopes.

   • 3H
     • Half life: 12.32
   • 14C
     • Half life:5,730 × 103
   • 50V
     • Half life:1.4 × 1017
   • 87Rb
     • Half life:4.75 × 1010

4. 4. What does it mean if a substances is radioactive?

   • If a substance is 'radioactive' it means that the atoms inside the substance is not stable, the nuclei in these atoms can decay. It changes one type of atom into another and releases radiation (the exact type of radiation depends on the substances). It has a chance of causing mutations in organic cells.

5. 5. How and where are radionuclides produced?

   • Radionuclides are produced when an atom has an unstable nucleus. They may occur naturally, but can also be artificially produced.

6. 6. Sketch a radioactive decay curve for a substance that starts with an activity of 1600 counts per minute and has a half-life of 2 hours.

7. 7. If a radioactive substance decays from 400 counts per minute to 50 counts per minute in 9 hours, what is its half-life?

8. 8. Alpha radiation consists of particles that can be easily stopped by our skin, but they are still considered a potential risk to our health. Explain why.

9. 9. Consider the composition of alpha and beta particles. When a beam of alpha particles and a beam of beta particles are fired into an electric field, they move in opposite directions. Why do you think this is?

10. 10. Write a short paragraph describing how the work of Marie Curie influenced future work in different areas of science.

11. 11. Describe why the Bohr model gives us much more information than Dalton’s early model of the atom.

12. 12. Radiation produced from the decay of radioactive atoms can be very dangerous, but it can also be used in life-saving medical treatments. Imagine you are a doctor wanting to reassure a patient about a treatment based on exposure to radiation. List the main ideas that you would want to tell your patient.

    • -The treatment could potentially be harmful in the long run. -There may be certain risks involved in this treatment.

Bilder und Dateien der Mindmap