2024 Earth's Layers and Half-Life

Front

What is half-life?

Back

Half-life is the time required for half of the radioactive atoms in a sample to decay.

Front

If a radioactive isotope has a half-life of 10 years, how much of a 100g sample remains after 30 years?

Back

12.5g

Front

What does it mean if a material is 'differentiated'?

Back

It means that the material has distinct layers with varying densities, such as the Earth's core being denser than the mantle.

Front

What is the significance of P and S wave shadow zones?

Back

They provide evidence that the Earth's outer core is liquid, as S waves cannot travel through liquids.

Front

How do you calculate the remaining percentage of a radioactive isotope after multiple half-lives?

Back

Use the formula: Remaining % = (1/2)^(number of half-lives) * 100.

Front

What is the half-life of Carbon-14?

Back

5700 years.

Front

If 25% of a radioactive isotope remains, how many half-lives have passed?

Back

2 half-lives.

Front

What is the relationship between half-life and the stability of a radioactive isotope?

Back

Isotopes with longer half-lives are generally more stable than those with shorter half-lives.

Front

What evidence supports the theory of continental drift?

Back

Fossil distribution, geological similarities, and the fit of continental shapes.

Front

What is the primary composition of the Earth's core?

Back

The Earth's core is primarily composed of iron and nickel.