Final answer:
Radiocarbon dating measures the decay of radioactive carbon isotopes in organic material, Potassium-argon dating measures the decay of radioactive potassium isotopes in volcanic rocks, and relative dating determines the age of rock layers by their position relative to each other.
Step-by-step explanation:
Radiocarbon dating: Measures the decay of radioactive carbon isotopes in organic material. This method works by examining the amount of carbon-14 remaining against its known half-life of 5,730 years. When organisms are alive, they constantly replenish their carbon-14 supply through respiration, but when they die, the carbon-14 begins to decay, allowing scientists to determine the age of the sample.
Potassium-argon dating: Measures the decay of radioactive potassium isotopes in volcanic rocks. This method is used to determine the age of rocks and minerals that contain potassium-40, which decays into argon-40. By measuring the ratio of argon-40 to potassium-40, scientists can estimate the age of the sample.
Relative dating: Determines the age of rock layers by their position relative to each other. This method relies on the principle of superposition, which states that in an undisturbed sequence of rock layers, the oldest rocks are at the bottom and the youngest are at the top.