At the beginning of an experiment, a scientist has 372 grams of radioactive goo. After 135 minutes, her sample has decayed to 23.25 grams. What is the half-life of the goo in minutes?

The term half-time is defined to be the amount of time required for one half of a radioactive material to undergo whatever type of decay is involved, meaning that one-half...

$N=BxxG^t$, 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...

Before doing anything else, make sure that you understand what's going on here. You're dealing with a sample of radioactive material that has an activity equal to $"880 Bq"$....

When dealing with a half life question, it is best to use the half-life formula, which is expressed as: $color(blue)(|bar(ul(color(white)(a/a)y=a(b)^(t/h)color(white)(a/a)|)))$ where: $y=$final amount $a=$inital amount $b=$growth/decay $t=$time elapsed $h=$half-life...

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...

Radioactive decay constant ($λ$) $λ = "ln(2)"/("T"_"1/2") = "ln(2)"/"125 years"$ Amount of radioactive substance left after time $t$ is $"N = N"_0 e^-(λt)$ $"N =...

After $"1 half life"$, clearly HALF of the original isotope remains. And after TWO half-lives, a $"HALF + HALF of a HALF"$, i.e. $3/4$ of the original mass has decayed.

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...

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...