[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 0
three isotopes. 1
Carbon-12 6 6
1. What do you notice about the
isotope number and the sum of Uranium- 92 143
protons and neutrons?
The isotope number is equal to the sum of the protons and neutrons.
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
H Uranium-235
Carbon-12
E
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? Proton joins nucleus
2. Colliding particles don’t always react. Click Reset, and then click Fire neutron.
, A. Does a reaction occur?
No
B. Explain: Neutron traveled through the nucleus