In a lab experiment, the decay of a radioactive isotope is being observed. At the beginning of the first day of the experiment the mass of the substance was 1500 grams and mass was decreasing by 13% per day. Determine the mass of the radioactive sample at the beginning of the 13th day of the experiment. Round to the nearest tenth (if necessary).Answer: □ grams
Q. In a lab experiment, the decay of a radioactive isotope is being observed. At the beginning of the first day of the experiment the mass of the substance was 1500 grams and mass was decreasing by 13% per day. Determine the mass of the radioactive sample at the beginning of the 13th day of the experiment. Round to the nearest tenth (if necessary).Answer: □ grams
Identify initial mass and decrease: Identify the initial mass and the daily percentage decrease.The initial mass of the radioactive substance is 1500 grams, and it decreases by 13% each day.
Determine decay factor: Determine the decay factor.The decay factor is the percentage that remains after the decay has occurred. Since the mass decreases by 13% each day, the decay factor is 100%−13%=87% or 0.87 in decimal form.
Calculate mass after each day: Calculate the mass after each day using the decay factor.The formula for exponential decay is P(t)=P0×(decay factor)t, where P(t) is the mass at time t, P0 is the initial mass, and t is the number of days.
Apply formula for 13th day: Apply the formula to find the mass at the beginning of the 13th day. P(12)=1500×(0.87)12, because we want the mass at the beginning of the 13th day, which is after 12 complete days.
Perform calculation: Perform the calculation.P(12)=1500×(0.87)12P(12)=1500×0.1369 (rounded to four decimal places)P(12)=205.35
Round result: Round the result to the nearest tenth.The mass of the radioactive sample at the beginning of the 13th day is approximately 205.4 grams when rounded to the nearest tenth.
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