Half Life Problems

Front

What is half-life?

Back

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

Front

What is the decay mode of Rn-222?

Back

Alpha decay.

Front

If a radioisotope has a half-life of 6 hours, how much of a 100g sample remains after 18 hours?

Back

12.5g.

Front

What is the half-life of a radioisotope if 25% of the original sample remains?

Back

Twice the half-life period.

Front

What does it mean when a radioisotope decays?

Back

It means that the unstable nucleus loses energy by emitting radiation.

Front

What is the relationship between half-life and decay rate?

Back

Shorter half-lives indicate faster decay rates.

Front

How do you calculate the remaining mass after multiple half-lives?

Back

Remaining mass = Original mass × (1/2)^(number of half-lives).

Front

What is the half-life of I-131?

Back

Approximately 8 days.

Front

What is the significance of a stable decay product?

Back

It indicates that the radioactive material has fully decayed into a non-radioactive form.

Front

What is the decay mode of I-131?

Back

Beta decay.