Suppose the half life of element K is 20 minutes. If you have 200 g sample of K, how much of element K will be left after 60 minutes?

$N=BxxG^t$, where N=new value, B=start value, G=growth (or decay) factor, and t=number of periods (years in this case. We know that $G^58=1//2$, so $G=root 58 (1/2)=(1/2)^(1/58)$ After 30 years,...

The answer is 20 years. A half life is the time taken for the radioactive particles in a sample to decay by half. It would, therefore, take another 20 years...

Initial mass $M_0 = 372$ grams Final mass $M_f = 23.25$ grams. Exponential decay says (k is decay constant and t is time) $M_f = M_0timese^(-ktimest)$ $ln(M_f/M_0) = -ktimest$ $ln(23.25/372)...

One half-life is the time it takes for half of a radioactive sample to decay. But two half-lives does not mean the whole sample decays. In the second half-life you...

As you know, the of a radioactive nuclide, $t_"1/2"$ represents the time needed for half of an initial sample to decay. This essentially means that a nuclide's half-life...

(a) Mass after t years The formula for calculating the amount remaining after a number of half-lives, $n$ is $color(blue)(bar(ul(|color(white)(a/a)"A" = "A"_0/2^ncolor(white)(a/a)|)))" "$ where $"A"_0$ is...

If we start with $150g$ of the isotope, after one half-life the quantity will diminish to $(150g)/2 = 75g$ which is half the original quantity. This can be written...

The number of half-lives is simply the number of days given ($966d$) divided by the half-life ($138d$), which is $7$ half-lives. The amount of $"^(210)Po$ remaining after $t$ days is...

We start with 325 and divide by two this accounts for one out the four half lives. Which is 162.5 once again we divide by two and we get 81.25...

Given that radioactive element X has a half-life $30$ days Hence the number $(n)$ of half-lives in $90$ days $n=90/30$ $n=3$ The amount $N$ of radioactive element X left after...