Tritium, a radioactive isotope of hydrogen, is often used in emergency EXIT signs. Because of the radioactive substance present in these signs, proper disposal is a matter of concern to the Environmental Protection Agency. The half-life of tritium is approximately 12 years. That is, every 12 years, the amount of tritium decreases by 50%. If a new tritium EXIT sign contains 25 curies of tritium, approximately how many curies of tritium will remain after 24 years?Choose 1 answer:(A) 6.25 curies(B) 12.5 curies(C) 25 curies(D) 30 curies
Q. Tritium, a radioactive isotope of hydrogen, is often used in emergency EXIT signs. Because of the radioactive substance present in these signs, proper disposal is a matter of concern to the Environmental Protection Agency. The half-life of tritium is approximately 12 years. That is, every 12 years, the amount of tritium decreases by 50%. If a new tritium EXIT sign contains 25 curies of tritium, approximately how many curies of tritium will remain after 24 years?Choose 1 answer:(A) 6.25 curies(B) 12.5 curies(C) 25 curies(D) 30 curies
Identify Data: Identify the initial amount of tritium, the total time that has passed, and the half-life of tritium.Initial amount a = 25 curiesTotal time t = 24 yearsHalf-life h = 12 years
Calculate Half-Lives: Determine the number of half-lives that have passed in the given time period.Number of half-lives = Total time / Half-lifeNumber of half-lives = 12years24yearsNumber of half-lives = 2
Use Half-Life Formula: Use the half-life formula to calculate the remaining amount of tritium.The formula is y=a×(21)ht, where y is the remaining amount, a is the initial amount, t is the total time, and h is the half-life period.Substitute the values into the formula: y=25×(21)2
Calculate Remaining Quantity: Calculate the remaining quantity of tritium.y=25×(21)2y=25×41y=6.25
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