FOCUS ON: Calculating Half-life

Part 1 - Keywords:

1. Half-life

2. Radioactive decay

3. Isotope

4. Decay constant

5. Nucleus

Part 2 - Key Facts:

1. The half-life of a radioactive isotope is the time it takes for half of the nuclei in a sample to decay.

2. Radioactive decay is a random process by which unstable atomic nuclei lose energy by emitting radiation.

3. Each radioactive isotope has its own characteristic half-life, which can vary from fractions of a second to billions of years.

4. The decay constant is the probability per unit time that a nucleus will decay.

5. The concept of half-life is used in various fields, including medicine, archaeology, and environmental science.

Part 3 - Quick Quiz:

1. What does the term "half-life" refer to in radioactive decay?

   a) The time it takes for all nuclei in a sample to decay

   b) The time it takes for half of the nuclei in a sample to decay

   c) The time it takes for a single nucleus to decay

   Answer: b) The time it takes for half of the nuclei in a sample to decay

2. Which of the following statements about radioactive decay is true?

   a) Radioactive decay occurs at a constant rate over time

   b) The decay constant depends on the size of the sample

   c) Each radioactive isotope has its own characteristic half-life

   Answer: c) Each radioactive isotope has its own characteristic half-life

3. How does the decay constant relate to the half-life of a radioactive isotope?

   a) The decay constant is equal to the half-life

   b) The decay constant is inversely proportional to the half-life

   c) The decay constant is directly proportional to the half-life

   Answer: b) The decay constant is inversely proportional to the half-life

Part 4 - Going Further:

Question: How can you determine the half-life of a radioactive isotope from given information?

Answer: To determine the half-life of a radioactive isotope, you need data on the initial quantity of the isotope and the quantity remaining after a certain period. By analysing the decay curve or exponential decay equation, you can calculate the half-life using mathematical methods.

Part 5 - Revision Tips:

Practice solving problems related to radioactive decay and half-life calculations. Understand the concepts of exponential decay and decay constant to effectively apply them to different scenarios.

Part 6 - More Help:

Stay tuned for the next issue, where we'll delve into another intriguing topic in GCSE Science.