Radioactive Decay & Half-life Midterm Review

Front

What is radioactive decay?

Back

Radioactive decay is the process by which an unstable atomic nucleus loses energy by emitting radiation, resulting in the transformation of the element into a different element or isotope.

Front

Define half-life.

Back

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

Front

What is the half-life of Iodine-131?

Back

The half-life of Iodine-131 is 8 days.

Front

How do you calculate the remaining amount of a radioactive substance after a certain number of half-lives?

Back

To calculate the remaining amount, use the formula: Remaining Amount = Initial Amount × (1/2)^(number of half-lives).

Front

What type of decay is represented by the equation: \(^{14}_{6}C \rightarrow ^{14}_{7}N + ^{0}_{-1}B\)?

Back

This equation represents beta decay.

Front

What is alpha decay?

Back

Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle, consisting of 2 protons and 2 neutrons, resulting in a new element.

Front

What is beta decay?

Back

Beta decay is a type of radioactive decay in which a neutron is transformed into a proton, emitting a beta particle (electron) and an antineutrino.

Front

If a sample has a half-life of 10 seconds, how much of a 40 mg sample remains after 30 seconds?

Back

After 30 seconds (3 half-lives), 5 mg of the sample remains.

Front

What is the decay product of \(^{240}_{94}Pu\) in the decay equation \(^{240}_{94}Pu \rightarrow ____ + ^{4}_{2}He\)?

Back

The decay product is \(^{236}_{92}U\).

Front

How long will it take for a 20 mg sample of Selenium-83 (half-life 25 minutes) to decay to 1.25 mg?

Back

It will take 100 minutes.