Unit 4 Checkpoint E/F

Front

What is a half-life?

Back

The time required for half of the radioactive atoms in a sample to decay.

Front

If a rock sample is 25% radioactive, how many half-lives has it gone through?

Back

2 half-lives.

Front

True or False: A rock sample can eventually have 0% radioactive material.

Back

FALSE. Radioactive decay never reaches 0%.

Front

What is radiometric dating used for?

Back

To measure the absolute age of rocks and fossils.

Front

What is the original element that undergoes radioactive decay called?

Back

Parent isotope.

Front

What is a daughter isotope?

Back

The product of the decay of a parent isotope.

Front

How do you calculate the remaining amount of a radioactive substance after a certain number of half-lives?

Back

Use the formula: Remaining amount = Initial amount × (1/2)^(number of half-lives).

Front

What does it mean if a rock has gone through 3 half-lives?

Back

It means that the original amount of radioactive material has been reduced to 1/8 of its initial amount.

Front

What is the difference between relative age and absolute age?

Back

Relative age is the age of an object in relation to other objects, while absolute age is the exact age in years.

Front

What is carbon-14 used for in dating?

Back

Carbon-14 is used for dating organic materials up to about 50,000 years old.