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Radioactive Half-Life quiz

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  • What is the definition of half-life in radioisotopes?
    Half-life is the time required for half (50%) of a radioisotope to decay.
  • What does the variable t½ represent in half-life calculations?
    t½ represents the half-life, or the time it takes for half of a radioisotope to decay.
  • How does the decay rate of a radioisotope vary?
    The decay rate varies depending on the element and its specific half-life.
  • If you start with 10 grams of a radioisotope with a one-day half-life, how much remains after one day?
    After one day, 5 grams remain, which is half of the original amount.
  • How much of the original radioisotope remains after two half-lives?
    After two half-lives, 25% of the original amount remains.
  • What is the formula for the fraction of radioisotope remaining after n half-lives?
    The fraction remaining is calculated as 0.5^n, where n is the number of half-lives.
  • How do you calculate the percentage of radioisotope remaining after n half-lives?
    Multiply the fraction remaining (0.5^n) by 100% to get the percentage.
  • What is a radioisotope?
    A radioisotope is an isotopic version of an element with an unstable nucleus that emits radiation as it decays.
  • How much of a radioisotope remains after three half-lives if you start with 10 grams?
    After three half-lives, 1.25 grams remain, which is 12.5% of the original amount.
  • What happens to the amount of radioisotope after each half-life?
    The remaining amount is reduced by half after each half-life.
  • How do you calculate the final amount of radioisotope remaining?
    Multiply the initial amount by the fraction remaining (0.5^n).
  • If you start with 100 grams of a radioisotope, how much remains after two half-lives?
    After two half-lives, 25 grams remain (100 x 0.5^2 = 25).
  • What does the symbol 'n' represent in the half-life formulas?
    n represents the number of half-lives that have passed.
  • How can you use the half-life formula for any initial quantity?
    You can multiply any initial amount by 0.5^n to find the remaining amount after n half-lives.
  • What is the relationship between the mass number, atomic number, and isotope symbol?
    The isotope symbol is written as X (element), with A as the mass number and Z as the atomic number.