Radioactive Decay
This type of decay releases a helium nucleus
Alpha decay
This part of an atom is split during nuclear fission
Nucleus
Isotopes of this element are fused together in stars to form helium
This is the main objective of a nuclear reactor
This term refers to the time taken for one half of the atomic nuclei to decay
Half-life
In beta decay, this particle is emitted when a neutron turns into a proton
Electron, beta particle
This isotope of uranium is the most common fuel in nuclear reactors.
Uranium-235
Fusion combines atomic nuclei to form this
Heavier atomic nuclei
This material is used as a moderator to slow down neutrons in a nuclear reactor
Water, graphite
If the half-life of a substance is 10 years, this percentage of the substance will remain after 20 years
25%
This form of decay emits high-energy electromagnetic radiation without releasing any particles
Gamma decay
This term describes a self-sustaining series of nuclear fission reactions
Chain reaction
Nuclear fusion occurs naturally in this celestial body
Sun
These act to absorb neutrons to regulate the rate of fission in a nuclear reactor
Control rods
This is the half-life of carbon-14, which is used in dating fossils
5730 years
Alpha particles are stopped by this common material
Paper
Besides energy, these particles are released during nuclear fission
Neutrons
Nuclear fusion is difficult to achieve on Earth because it requires this extreme condition
High temperature
This substance is the primary coolant used in most reactors to transfer heat
Water
After this many half-lives, 12.5% of the original material remains
3 half-lives
This type of particle is emitted during beta-plus decay, turning a proton into a neutron
Positron
This type of nuclear weapon uses fission to release enormous amounts of energy
Atomic bomb
This element is the byproduct of hydrogen fusion in stars
Helium
This type of nuclear reactor is the most common design used in poewr plants today
Pressurized water reactor (PWR)
If a material decays for 100 grams to 12.5 grams in 12 years, this is the half-life of the material
4 years