Half-Life Questions

There is 10g of a radioactive isotope.

How much will be left after 1 half-life?

• 3.3g

• 5g

• 2.5g

• 15g

There is 10g of a radioactive isotope.

How much will be left after 2 half-lives?

• 12g

• 5g

• 2.5g

• 7.5g

There are 12kg of radioactive nuclei.

How much will be left after 3 half-lives?

• 1.5kg

• 3kg

• 4kg

• 6kg

There are 4kg of a radioactive isotope.

The half-life is 20s.

How much will be left after 20s?

• 8kg

• 2kg

• 1kg

• 0.2kg

There are 4kg of a radioactive isotope.

The half-life is 20s.

How much will be left after 40s?

• 0.5kg

• 1kg

• 2kg

• 8kg

There are 4kg of a radioactive isotope.

The half-life is 20s.

How much will be left after 60s?

• 2kg

• 0.5kg

• 1kg

• 8kg

There are 4kg of a radioactive isotope.

After 6 seconds, there are 2kg left.

What is the half-life of the isotope?

• 12s

• 6s

• 2s

• 4s

There are 4kg of a radioactive isotope.

After 7s, there is 1kg left.

What is the half-life of the isotope?

• 14s

• 7s

• 3.5s

• 1.75s

The half life of a radioactive isotope is 4 days.

There are 1400 unstable nuclei.

How many will there be in 8 days?

• 700

• 1100

• 175

• 350

The half-life of a radioactive isotope is 12 hours.

There are 200 unstable nuclei.

How many were there 36 hours ago?

• 25

• 400

• 800

• 1600