tritium is a radioactive isotope of hydrogen that decays by about 5% per year. a large bottle of water that…

tritium is a radioactive isotope of hydrogen that decays by about 5% per year. a large bottle of water that contained 856,000 tritium atoms remained undisturbed for 13 years. how much tritium does the bottle contain now? if necessary, round your answer to the nearest whole number. tritium atoms
Answer
Explanation:
Step1: Identify the decay - formula
The formula for exponential decay is $A = P(1 - r)^t$, where $P$ is the initial amount, $r$ is the rate of decay, and $t$ is the time. Here, $P = 856000$, $r=0.05$, and $t = 13$.
Step2: Substitute the values into the formula
$A=856000\times(1 - 0.05)^{13}$. First, calculate $1-0.05 = 0.95$. Then, find $(0.95)^{13}$. Using a calculator, $(0.95)^{13}\approx0.51337$.
Step3: Calculate the final amount
$A = 856000\times0.51337$. $A\approx439445$.
Answer:
439445