Radiation Basics
This term describes an unstable nucleus losing energy by emitting radiation.
radioactive decay?
This type of radiation consists of two protons and two neutrons, identical to a helium nucleus, and can be stopped by a simple sheet of paper.
an alpha particle
the time it takes for half of a radioactive sample to decay
This is the definition of a half-life.
This nuclear process involves splitting a heavy, unstable nucleus into lighter nuclei, releasing immense energy.
nuclear fission
This 1986 disaster in Ukraine is widely known as the worst accidental nuclear power plant explosion in history.
Chernobyl
This general term refers to high-energy radiation capable of knocking electrons off atoms, which can damage living tissue.
ionizing radiation
This type of radiation is a fast-moving electron emitted from the nucleus and can be stopped by a sheet of aluminum foil.
a beta particle
If a -gram radioactive sample goes through exactly one half-life, this is the mass of the radioactive isotope that remains.
50 grams
This nuclear process involves forcing light atomic nuclei together to form a heavier nucleus.
nuclear fusion
In 2011, a massive earthquake and tsunami triggered a severe nuclear meltdown at this power plant in Japan.
Fukushima Daiichi
Atoms of the same element that have the same number of protons but a different number of neutrons are called this.
isotopes
This type of radiation is not a particle but a high-energy electromagnetic wave that requires thick lead or concrete shielding.
a gamma ray
This radioactive isotope of carbon has a half-life of about 5,730 years and is commonly used by scientists to find the age of ancient organic artifacts.
Carbon-14
This massive celestial object is completely powered by the nuclear fusion of hydrogen atoms into helium.
The sun
This famous female scientist discovered the radioactive elements Polonium and Radium, and later died from radiation exposure due to her research.
Marie Curie
This force holds protons and neutrons together in the nucleus, overcoming the electric repulsion between positive protons.
the strong nuclear force
Because it has a large mass and a +2 charge, this specific type of radiation has the highest ionizing power but the lowest penetration power.
alpha radiation
If a sample goes through three half-lives, this is the fraction of the original radioactive material that is left.
one-eighth (1/8 or 12.5\%)
Commercial nuclear power plants around the world currently use this specific process to generate electricity.
nuclear fission
This radioactive element was famously painted onto watch dials in the 1920s by factory workers who grew severely ill from licking their paintbrushes.
Radium
When an atom undergoes radioactive decay and its number of protons changes, it transforms into an entirely different element, a process known by this term.
transmutation
During this specific type of decay, a neutron inside the nucleus splits into a proton and an electron, causing the element's atomic number to increase by 1.
beta decay
To satisfy this fundamental scientific law, the sum of the mass numbers and atomic numbers must be completely equal on both sides of a written nuclear equation.
the Law of Conservation of Mass
Fission power plants rely on these uncharged subatomic particles to collide with heavy atoms, triggering a continuous, self-sustaining chain reaction.
neutrons
This radioactive isotope is a major danger after nuclear power plant accidents because it is quickly absorbed by the human thyroid gland, though its effects can be blocked by taking potassium iodide pills.
Iodine-131