Radiometric Dating and Isotopes

The video tutorial explains radiometric dating, focusing on the concept of half-life and the decay of isotopes. It covers carbon-14 dating, its limitations for older samples, and introduces alternative isotope pairs like uranium-238 and lead-206 for dating meteorites. The importance of maintaining a closed system during the dating process is emphasized. The tutorial also details the use of mass spectrometers and equations for precise dating calculations.

What is the primary purpose of radiometric dating?

• To identify the chemical composition of a rock

• To measure the temperature of a rock

• To find the age of a rock or meteorite

• To determine the color of a rock

Which isotope of carbon is used in radiometric dating?

• Carbon-14

• Carbon-15

• Carbon-12

• Carbon-13

What defines an isotope of an element?

• Different numbers of neutrons

• Different numbers of electrons

• Different atomic numbers

• Different numbers of protons

What is the approximate half-life of carbon-14?

• 100,000 years

• 1,000 years

• 5,730 years

• 10,000 years

Why is carbon-14 not suitable for dating rocks that are 100 million years old?

• It only works for meteorites

• There is not enough parent isotope left to measure

• It is not found in rocks

• It decays too quickly

What is a critical requirement for a rock to be accurately dated using radiometric methods?

• It must be exposed to sunlight

• It must have undergone metamorphism

• It must contain water

• It must remain a closed system

What can cause the migration of isotopes in a rock?

• Exposure to sunlight

• High temperatures and chemical weathering

• Presence of water

• Lack of oxygen

Which isotope pair is used to date meteorites?

• Carbon-14 and Nitrogen-14

• Uranium-238 and Lead-206

• Uranium-235 and Lead-207

• Potassium-40 and Argon-40

What is the half-life of Uranium-238?

• 10 billion years

• 4.5 billion years

• 1.4 billion years

• 700 million years

How many half-lives have passed for a meteorite that is 4.6 billion years old using Uranium-235?

• 7.5 half-lives

• 6.7 half-lives

• 4.5 half-lives

• 3.5 half-lives