Final answer:
Relative dating determines the sequence of events in Earth's history without specifying exact ages, using principles like superposition. Radioactive dating, on the other hand, uses the decay rates of isotopes to determine the absolute age of rocks. The correct statement would be that radioactive dating uses half-life to find an exact age.
Step-by-step explanation:
The statement that both relative dating and radioactive dating compare the object to an event in history is not true. Relative dating and radioactive dating are two methods used by geologists to determine the age of rocks and fossils, but they operate differently. Relative dating determines the sequence of events, placing rocks and structures in chronological order without specifying their actual age in years. It often uses the principle of superposition, where lower layers are deemed older than those above them in undisturbed sequences.
In contrast, radioactive dating or radiometric dating, uses the decay of isotopes to determine the absolute age of rocks. This dating technique relies on the principle that radioactive isotopes decay at a constant rate, known as a half-life. By measuring the ratio of parent isotopes to their decay products, geologists can calculate how long this decay process has been occurring, giving an exact age of the rock in years.