Radioactivity

Definition

Radioactivity is the process by which unstable atomic nuclei lose energy by emitting radiation. It plays a crucial role in determining the ages of planetary surfaces through radiometric dating.

5 Must Know Facts For Your Next Test

1. Radioactive decay occurs at a predictable rate, described by an isotope's half-life.
2. The most common isotopes used in dating planetary surfaces are Uranium-238, Potassium-40, and Carbon-14.
3. Radiometric dating helps scientists estimate the age of rocks and meteorites, providing insight into the history of the solar system.
4. The decay products of radioactive isotopes can be measured to determine the time elapsed since the rock solidified.
5. Different isotopes are used for dating different types of rocks based on their expected age range and composition.

Review Questions

• What is the significance of half-life in radiometric dating?
• Name three isotopes commonly used in radiometric dating and explain why they are chosen.
• How does radioactivity help scientists understand the history of planetary surfaces?

Related terms

Half-life:

The time required for half of a sample of a radioactive substance to decay into its daughter isotopes.

Radiometric Dating:

A technique used to date materials such as rocks or carbon by comparing the relative proportions of specific radioactive isotopes present in a sample.

Isotope:

Variants of a particular chemical element that have different numbers of neutrons but the same number of protons.