Worksheet: Fusion Reactions in Stars

In this worksheet, we will practice determining the products of fusion reactions and identifying decay processes by their decay products.

Q1:

In the P–P III branch of the proton–proton chain reaction, a boron-8 nucleus becomes a beryllium-8 nucleus, releasing a positron and an electron neutrino in the process. This is shown in the following nuclear equation.

What is the name of this process?

  • A 𝛽 decay
  • B 𝛽 decay
  • C 𝛼 decay
  • DPair production
  • EElectron capture

Q2:

In the P–P II branch of the proton–proton chain reaction, a beryllium-7 nucleus and an electron combine to produce a lithium-7 nucleus and an electron neutrino. This is shown in the following nuclear equation.

What is the name of this process?

  • ABeta decay
  • BElectron capture
  • CInverse beta decay
  • DPair production
  • EAlpha decay

Q3:

The following set of nuclear equations shows one way that helium-4 can be produced through the proton–proton fusion chain.

How many protons are needed in total to produce one helium-4 nucleus using this chain reaction only?

  • A8
  • B10
  • C4
  • D2
  • E6

Q4:

The diagram shows six combinations of protons and neutrons.