CK-12 Physical Science Concepts - For Middle School

3.59. Radioactive Decay http://www.ck12.org

Vocabulary

• radioactive decay: Process in which the unstable nucleus of a radioisotope becomes stable by emitting
  charged particles and energy and changing to another element.

Explore More

Watch the video about the decay of uranium at the following URL, and then answer the questions below.

http://www.youtube.com/watch?v=F8sAkMQmOlU

MEDIA

Click image to the left for use the URL below.

URL: http://www.ck12.org/flx/render/embeddedobject/84664

1. In the first step of the decay of uranium-238, what are the products?


2. How does the atomic number of uranium-238 change in the first step of the decay?


3. What happens to the new element that results from the first step of uranium-238 decay?


4. What type of decay is the decay of uranium-238?


5. What is the half-life of a radioactive element? What is the half-life of uranium-238?


6. Uranium-238 decays very slowly, so why is a lump of uranium-238 dangerous?

Review

1. What is radioactive decay?


2. Compare and contrast alpha, beta, and gamma decay.