A sample of 250 grams of radioactive substance decays at a rate of 34% per year. Write the equation for radioactive decay of this substance.

Question

anonymous · Answer

Here are my answer choices: 
	250(1.34)^t
	250e^.34t
	250(0.66)^t
	250e^-.34t

anonymous · Answer

If it decays at 34% per year what percent is left after a year?

anonymous · Answer

We thought it would be C, but someone got it wrong when they did that. I don't know if it could be d possibly?

anonymous · Answer

It is C. No if's, and's, or but's about that.

A = starting amount = 250 grams

so you have 250(1 - .34)^t
                0r 250(.66)^t

anonymous · Answer

If someone wrote C and got it wrong, let that person go back and ask for credit.

anonymous · Answer

Assuming that C is 250(.66)^t.

anonymous · Answer

@bkeith2698

anonymous · Answer

We learned the other day that it's also possible to put this in the form $$P=P_{0}e ^{kt}$$ where p is the current value. p0 is the initial, e is the base of a natural log, k is the percent decrease/increase and t is the time. Would that make d right? I think it would.

anonymous · Answer

@Easyaspi314

anonymous · Answer

the 34 percent of 250 is107 so
250 are the initial grams and t is the time in years so..
EQUATION=250-107t
And that´s it

anonymous · Answer

Can't be. not an answer choice. thanks for the help though @julian9922

anonymous · Answer

click on best response please

anonymous · Answer

Two people have helped me, I will give the best response to the one that solves CORRECTLY. @julian9922 and @Easyaspi314

anonymous · Answer

i helped you the most and it was easy to understand my explanation

anonymous · Answer

You told me what I already knew......not why I came on here......@julian9922

anonymous · Answer

so wht do you need?i will help you also