2024 Earth's Layers and Half-Life

Front

What is a half-life?

Back

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

Front

If 50% of a radioactive isotope remains, how many half-lives have passed?

Back

1 half-life.

Front

What evidence supports that the Earth's outer core is liquid?

Back

P and S wave shadow zones.

Front

What is the half-life of Radon-226?

Back

28 days.

Front

If 10 grams of Radon-226 is present, how much remains after 84 days?

Back

12.5%.

Front

What is the half-life of Carbon-14?

Back

5700 years.

Front

If only 12.5% of Carbon-14 remains, how many years have passed?

Back

17,100 years.

Front

Which seismic waves cannot travel through the Earth's outer core?

Back

S waves.

Front

What are P waves?

Back

Primary waves that can travel through solids and liquids.

Front

What are S waves?

Back

Secondary waves that can only travel through solids.