Radioactive decay

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/radioactive-decay

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. Who discovered Radioactive decay?First observed in 1896 by Henri Becquerel
2. What is the discoverers?Henri Becquerel, Marie Curie, Pierre Curie, Ernest Rutherford
3. What is the formula?N(t) = N₀ (1/2)^(t/T½) (for decay rate, where T½ is half-life)
4. Why do atoms become unstable and decay?Atoms become unstable when the balance between the strong nuclear force and the repulsion between protons is upset, often because of too many or too few neutrons. The nucleus then seeks a more stable state.
5. How does radioactive decay help us learn about the past?Scientists use radiometric dating, like carbon‑14 and uranium‑lead, to measure how long ago rocks or fossils formed, giving us a timeline of Earth and history.

Nuclide: A distinct atomic species characterized by a specific number of protons and neutrons.
Half-life: The time required for half of the radioactive atoms in a sample to decay.
Transmutation: The process by which one chemical element is transformed into another.