Year 10 Science · Unit 2 · Lesson 23

Radioactive Decay, Alpha and Beta Reactions

Challenge Worksheet

Name
Date
Class

Learning Goals

Go Deeper

Find the mistakes

A student wrote these five statements in their revision notes

  1. "In alpha decay the mass number drops by 2 and the atomic number drops by 4, because an alpha particle is two protons."
  2. "In beta-minus decay the nucleus loses a proton, so the atomic number goes down by 1."
  3. "Gamma radiation changes the element because it carries away two protons as pure energy."
  4. "The equation 146C → 146N + 0-1e is balanced and correct."
  5. "A chemical reaction with the right catalyst could turn uranium into lead, just like nuclear decay does."

1. Correct statement 1. State the real change in mass number and atomic number during alpha decay, and explain why.

Challenge 1 mark

2. Correct statement 2. Explain what really happens inside the nucleus in beta-minus decay and what that does to the atomic number.

Challenge 1 mark

3. Correct statement 3. Explain what gamma radiation actually is and why it does not change the mass number or atomic number.

Challenge 1 mark

Go Deeper (continued)

4. Find the error in statement 4 and write the fully balanced, correct equation for the beta decay of carbon-14. Show your check of both rows.

Challenge 2 marks

5. Correct statement 5. Explain why only a nuclear reaction, and never a chemical reaction, can transmute one element into another.

Challenge 2 marks

Show What You Know

1. Polonium-218 ( 21884Po ) decays by alpha emission, and the daughter then decays by beta emission. Write both balanced nuclear equations in sequence, identify each daughter nuclide, and check that each equation balances.

Challenge 3 marks

Wrap Up

Why is it that the same two conservation rules let you predict the product of any alpha or beta decay you meet?

HSCScience · Year 10 Science · Unit 2 · Lesson 23 · Challenge Worksheet