Student Exploration: Nuclear Reactions
[Note to teachers and students: This Gizmo was designed as a follow-up to the Nuclear Decay
Gizmo. We recommend doing that activity before trying this one.
Vocabulary: chain reaction, CNO cycle, catalyst, deuterium, electron volt, fission,
fusion, isotope, nuclear reaction, positron, positron emission, proton-proton chain
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
The chart to the right gives the isotope
name, element name, number of Isotope Protons Neutrons
protons, and number of neutrons of Hydrogen-1 1 0
three isotopes.
Carbon-12 6 6
1. What do you notice about the Uranium- 92 143
isotope number and the sum of 235
protons and neutrons?
They all vary in numbers
2. The element symbol for uranium-238 is . This means U-238 has a total
mass of 238 and contains 92 protons. Write the element symbols for the
isotopes in the table:
Hydrogen-1 1/1 H Carbon-12 12/6 C Uranium-235 235/92 U
Gizmo Warm-up
The Nuclear Reactions Gizmo simulates a particle accelerator.
Particle accelerators speed up atoms to very high velocities,
then crash the atoms together with enough energy to cause
changes called nuclear reactions. There are three particle
beams available in this Gizmo, protons, neutrons, and
helium-3 nuclei.
1. Click Fire Proton to engage the first particle beam.
What happens? A positron flew out
2. Colliding particles don’t always react. Click Reset, and then click Fire neutron.
A. Does a reaction occur? no
B. Explain: the fire neutron flew through
, Get the Gizmo ready:
Activity A:
• Click Reset.
Proton-proton
• Be sure Proton-proton is selected in the
chain
Reaction
menu.
Introduction: All stars turn hydrogen into helium in a process called nuclear fusion.
Stars perform this process in different ways. In stars like our sun, the proton-proton
chain is used. This reaction requires temperatures greater than 4,000,000 K to
occur.
Question: How does the process of fusion turn hydrogen into helium in stars?
1. Observe: Click Fire proton and observe. What happens after the proton
merges into the nucleus? A gamma is released
This is a form of nuclear decay called positron emission. During positron
emission, a proton decays into a neutron. In this process, it emits a positron,
which is a nearly massless antimatter particle with a positive charge.
2. Observe: Click Reset and click Fire proton. Observe what happens. Many
subatomic particles appear frequently in nuclear reactions. Their element
symbols are given below:
Neutron Positron Electron Proton
(Neutrinos are also produced but are beyond the scope of this Gizmo.)
Click Reset and click Fire proton. Turn on the Write equation checkbox. Based on
what you have observed, write in the equation for this reaction in the Gizmo and
below.
1/0 n to 0/1 e+ plus 1/1 H
A. Turn on Show equation. Was your predicted equation correct? yes
Correct your equation if necessary. The resulting H-2 isotope is called
deuterium.
B. Emitted energy is reported in megaelectron volts (MeV), where one MeV
[Note to teachers and students: This Gizmo was designed as a follow-up to the Nuclear Decay
Gizmo. We recommend doing that activity before trying this one.
Vocabulary: chain reaction, CNO cycle, catalyst, deuterium, electron volt, fission,
fusion, isotope, nuclear reaction, positron, positron emission, proton-proton chain
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
The chart to the right gives the isotope
name, element name, number of Isotope Protons Neutrons
protons, and number of neutrons of Hydrogen-1 1 0
three isotopes.
Carbon-12 6 6
1. What do you notice about the Uranium- 92 143
isotope number and the sum of 235
protons and neutrons?
They all vary in numbers
2. The element symbol for uranium-238 is . This means U-238 has a total
mass of 238 and contains 92 protons. Write the element symbols for the
isotopes in the table:
Hydrogen-1 1/1 H Carbon-12 12/6 C Uranium-235 235/92 U
Gizmo Warm-up
The Nuclear Reactions Gizmo simulates a particle accelerator.
Particle accelerators speed up atoms to very high velocities,
then crash the atoms together with enough energy to cause
changes called nuclear reactions. There are three particle
beams available in this Gizmo, protons, neutrons, and
helium-3 nuclei.
1. Click Fire Proton to engage the first particle beam.
What happens? A positron flew out
2. Colliding particles don’t always react. Click Reset, and then click Fire neutron.
A. Does a reaction occur? no
B. Explain: the fire neutron flew through
, Get the Gizmo ready:
Activity A:
• Click Reset.
Proton-proton
• Be sure Proton-proton is selected in the
chain
Reaction
menu.
Introduction: All stars turn hydrogen into helium in a process called nuclear fusion.
Stars perform this process in different ways. In stars like our sun, the proton-proton
chain is used. This reaction requires temperatures greater than 4,000,000 K to
occur.
Question: How does the process of fusion turn hydrogen into helium in stars?
1. Observe: Click Fire proton and observe. What happens after the proton
merges into the nucleus? A gamma is released
This is a form of nuclear decay called positron emission. During positron
emission, a proton decays into a neutron. In this process, it emits a positron,
which is a nearly massless antimatter particle with a positive charge.
2. Observe: Click Reset and click Fire proton. Observe what happens. Many
subatomic particles appear frequently in nuclear reactions. Their element
symbols are given below:
Neutron Positron Electron Proton
(Neutrinos are also produced but are beyond the scope of this Gizmo.)
Click Reset and click Fire proton. Turn on the Write equation checkbox. Based on
what you have observed, write in the equation for this reaction in the Gizmo and
below.
1/0 n to 0/1 e+ plus 1/1 H
A. Turn on Show equation. Was your predicted equation correct? yes
Correct your equation if necessary. The resulting H-2 isotope is called
deuterium.
B. Emitted energy is reported in megaelectron volts (MeV), where one MeV
