Understanding Nuclear Half-Life

The video tutorial explains the concept of nuclear half-life, which is the time required for half of a radioactive sample to decay into another element. It uses thorium-234 undergoing beta decay to become protactinium as an example, demonstrating how the amount of thorium decreases by half every 24 days. The tutorial also includes a graphical representation of this process and compares the half-lives of different elements, such as uranium-238 and polonium-218, highlighting the wide range of half-life durations in nuclear reactions.

What does nuclear half-life measure?

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

• The time it takes for an atom to change its state

• The time it takes for a neutron to become a proton

• The time it takes for a nuclear process to start

In beta decay, what transformation occurs in the nucleus?

• A neutron turns into a proton

• A proton turns into an electron

• A proton turns into a neutron

• An electron turns into a neutron

What happens to thorium-234 during its decay process?

• It remains as thorium-234

• It transforms into protactinium

• It turns into lead-214

• It becomes uranium-238

How long is the half-life of thorium-234?

• 12 days

• 72 days

• 24 days

• 48 days

What does the graph of a half-life process typically show?

• An exponential increase in the amount of substance

• A linear increase in the amount of substance

• A constant amount of substance over time

• A stepwise decrease in the amount of substance

Which element has a half-life of 4.5 billion years?

• Uranium-238

• Polonium-218

• Lead-214

• Thorium-234

What is the half-life of polonium-218?

• 3 years

• 3 minutes

• 3 days

• 3 hours

If you leave a sample of polonium-218 for 3 minutes, what happens?

• It turns into uranium

• It completely disappears

• Half of it turns into lead

• It remains unchanged

What is the significance of the half-life in nuclear reactions?

• It measures the time for half of a sample to decay

• It shows how quickly a substance can disappear

• It indicates the speed of the reaction

• It determines the stability of the nucleus

How do different elements compare in terms of their half-lives?

• All elements have the same half-life

• Half-lives vary widely among different elements

• Half-lives are always measured in years

• Half-lives are always less than a day