Half Lives in radioactive Decay

What is the definition of half-life in radioactive decay?

The time it takes for half of a radioactive sample to decay.

Is the half-life specific to each radioactive element?

Yes, half-life is unique to each radioactive element.

If a radioactive sample has a mass of 100g, what is its mass after one half-life?

50g.

How do half-lives vary among different elements?

Some have half-lives of seconds, while others have half-lives of billions of years.

What can the concept of half-life be used for?

To determine the age of things.

In which types of isotopes does half-life occur?

Only in radioactive isotopes.

What does Uranium-238 decay into, and what is its half-life?

Uranium-238 decays into Lead-206 with a half-life of 4.47 billion years.

What remains of a 10g sample of Uranium-238 after 4.47 billion years?

5g.

What does Iodine-131 decay into, and what is its half-life?

Iodine-131 decays into Xenon-131 with a half-life of 8 days.

What remains of a 10g sample of Iodine-131 after 8 days?

5g.

What types of decay occur in radioactive isotopes?

Alpha, Beta, and Gamma decay.

Can we predict the exact moment when a specific radioactive isotope will decay?

No, the decay occurs randomly and cannot be predicted for individual isotopes.

What can we predict about the decay of a large sample of radioactive material?

We can predict how long it will take for a large sample to decay.