Isotopes, Half-Lives, and Mathematical Modeling

What is an isotope?

• An atom with a different number of protons and neutrons

• An atom with the same number of protons but a different number of neutrons

• A molecule made up of radioactive elements

• A compound formed from radioactive decay

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NGSS.HS-PS1-8

What does the term "half-life" mean in radioactive dating?

• The time it takes for half of the parent isotope to decay into daughter isotopes

• The time it takes for all isotopes in a sample to decay

• The average age of a fossil sample

• The amount of time a radioactive element stays stable

Tags

NGSS.HS-PS1-8

If a rock sample contains 50% parent isotopes and 50% daughter isotopes, how many half-lives have passed?

• 0.5

• 1

• 2

• 3

A scientist finds a sample with a parent-to-daughter isotope ratio of 25:75. How many half-lives have passed?

• 1

• 4

• 3

• 2

Tags

NGSS.HS-PS1-8

If the half-life of a parent isotope is 2 billion years, and three half-lives have passed, how old is the sample?

• 2 billion years

• 4 billion years

• 6 billion years

• 8 billion years

Why is mathematical modeling important in radioactive dating?

• It allows scientists to observe isotopes directly in real time.

• It simplifies calculations for determining the age of a sample.

• It eliminates the need for experimental data.

• It helps measure the speed of chemical reactions.

Tags

NGSS.HS-PS1-8

Which isotope is most commonly used to date ancient biological samples?

• Carbon-14

• Uranium-238

• Potassium-40

• Thorium-232

What happens to the daughter isotope count as the parent isotope decays?

• It decreases

• It remains constant

• It fluctuates randomly

• It increases

Tags

NGSS.HS-PS1-8