Category 1
Determining the age of rocks or fossils compared to other rocks or fossils, not the exact age
Relative Age Dating
The time it takes for half of a sample of a radioactive substance to decay into stable form
Half-life
A machine with blades that spins when pushed by water, wind, or steam to generate electricity
Turbine
The ability to do work or cause change
Energy
States that sedimentary rock layers are originally deposited in flat, horizontal layers
Law of Original Horizontality
Energy produced from the heat inside the Earth
Geothermal Energy
Energy-rich substances (coal, oil, natural gas) formed from the remains of ancient plants and animals
Fossil Fuels
A natural resource that can be replaced or replenished in a short period of time (like sunlight or wind)
Renewable Resource
In undisturbed layers or rock, the oldest layer is at the bottom and the youngest is at the top
Law of Superposition
Pieces of one rock found inside another; the inclusions are older than the rock surrounding them
Inclusions
A method of finding the actual (absolute) age of a rock or fossil by measuring radioactive delay
Radiometric Dating
Energy released when the nucleus of an atom is split (fission) or combined (fusion)
Nuclear Energy
Gaps in the geological record that show where rock layers have been lost due to erosion or missing time
Unconformities
The original radioactive isotope that decays
Parent Material
A resource that cannot be replaced quickly; it takes millions of years to form (like coal or oil)
Nonrenewable Resource