Radioactive Decay and Half-Life Concepts

The video tutorial explains radioactive decay, focusing on carbon-14 and nitrogen-14 isotopes. It details the decay process, half-life concept, and limitations of carbon-14 dating for older rocks. The tutorial also covers alternative methods for dating meteorites using uranium-238 and lead-206, emphasizing the importance of closed systems in accurate dating.

What is the term used to describe the time it takes for half of a radioactive parent material to decay into its daughter product?

• Half-Life

• Decay Rate

• Isotope Ratio

• Radioactive Period

Which isotope of carbon has six protons and eight neutrons?

• Carbon-12

• Carbon-13

• Carbon-15

• Carbon-14

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

• It decays too quickly.

• It only decays into carbon-12.

• It is not found in rocks.

• There would not be enough parent material left to measure.

What is the primary reason carbon-14 is useful for dating relatively young rocks?

• It is stable and does not decay.

• It has a long half-life.

• It is abundant in all rocks.

• It decays into nitrogen-14, which is not initially present.

What is a critical requirement for a rock to be accurately dated using radioactive decay?

• It must remain a closed system.

• It must be exposed to high temperatures.

• It must contain carbon.

• It must have undergone chemical weathering.

What is the half-life of uranium-238 when it decays to lead-206?

• 4.5 billion years

• 5,700 years

• 700 million years

• 1.4 billion years

How many half-lives have passed for uranium-235 to lead-207 in a 4.6 billion-year-old meteorite?

• 4.5

• 5.5

• 6.7

• 7.5

What is the expected ratio of uranium-238 to lead-206 in a meteorite that is 4.5 billion years old?

• 1:7

• 1:15

• 1:3

• 1:1

Which of the following is NOT a suitable radioactive decay pair for dating meteorites?

• Potassium-40 to Argon-40

• Uranium-238 to Lead-206

• Uranium-235 to Lead-207

• Carbon-14 to Nitrogen-14

What is the fraction of parent material remaining after 6.7 half-lives?

• 0.5

• 0.25

• 0.00963

• 0.001