CK-12 Physical Science Concepts - For Middle School

3.63. Radioactive Half-life http://www.ck12.org

Vocabulary

• half-life: Length of time it takes for half of a given amount of a radioisotope to decay.

Explore More

Complete the radioactivity worksheet at this URL: http://zimearth.pbworks.com/f/Radioactivity+Worksheet.pdf

Review

1. Define half-life.


2. Why do radioisotopes differ in the length of their half-lives?


3. What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? (Hint: Find the
   half-life of hydrogen-3 in theTable3.14.)