Half Lives
The time it takes for half of a radioactive substance to decay.
What is a half-life?
A radioactive isotope has a half-life of 10 years. If you start with 200 grams, this much remains after 30 years.
What is 25 grams?
This process occurs when light atomic nuclei combine to form a heavier nucleus, releasing energy.
What is nuclear fusion?
After two half-lives, this fraction of the original radioactive material remains.
What is one-quarter?
A sample originally has a mass of 400 grams, and after 4 half-lives, this amount of the sample remains.
What is 25 grams?
This process splits a large, unstable nucleus into smaller nuclei, releasing energy.
What is nuclear fission?
This term describes a material that emits radiation as it breaks down over time.
What is radioactive?
The half-life of a substance is 5 years. If you start with 160 grams, this amount remains after 15 years.
What is 20 grams?
This creates more radioactive energy.
What is fission?
After three half-lives, this fraction of the original sample remains.
What is one-eighth?
A substance with a half-life of 6 hours starts at 320 grams. After 18 hours, this amount remains.
What is 40 grams?
This type of nuclear reaction "powers the sun."
What is fusion?
After four half-lives, this percentage of the original substance is still present.
What is 6.25%?
After five half-lives, this percentage of the original radioactive sample remains.
What is 3.125%?
What is a similarity between fusion and fission?
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