Understanding Fossil Dating

The video explains how scientists determine the age of fossils using carbon dating. It begins by comparing methods for dating people and trees, then introduces the concept of carbon in living organisms. The focus shifts to Carbon 14, an unstable isotope that decays over time, allowing scientists to measure the age of fossils. The process of carbon dating is detailed, including its limitations for fossils older than 60,000 years. For older fossils, other elements with longer half-lives are used.

How do scientists determine the age of a tree?

• By measuring its height

• By analyzing its roots

• By counting its rings

• By examining its leaves

What do scientists look at to read a fossil's internal clock?

• The color of the fossil

• The location where the fossil was found

• The ratio of two types of carbon atoms

• The size of the fossil

What is the most common form of carbon found in living things?

• Carbon 18

• Carbon 16

• Carbon 12

• Carbon 14

How is Carbon 14 created?

• By plants during photosynthesis

• By animals during respiration

• By volcanic eruptions

• By cosmic rays hitting nitrogen atoms

What happens to Carbon 14 in an animal's body after it dies?

• It turns into Carbon 12

• It increases in amount

• It starts to decay

• It remains stable

What is the half-life of Carbon 14?

• 5,730 years

• 2,500 years

• 1,000 years

• 10,000 years

How much Carbon 14 remains after two half-lives?

• Half

• A quarter

• None

• An eighth

For fossils older than 60,000 years, what do scientists use to date them?

• Carbon 12

• Stable elements

• Unstable elements with longer half-lives

• Fossil size