The model for radioactive decay is y=y0e−kt. A radioactive substance has a half-life of 200 years. If 45 grams are present today, in how many years will 25 grams be present? While solving this problem, round the value of k to seven decimal places. Round your answer to two decimal places.

Therefore 25 grams will be present in 135.62 years.

Step-by-step explanation:

The model for radioactive decay is

y=remaining amount of radioactive element.

= initial amount of radioactive element

Given that, the half life of the radioactive element is 200 years.

For half life, , t=200 years

Taking ln both sides

⇒ k= 0.0034657

Given that,

y= 25 gram, y₀= 45 grams

Taking ln both sides

⇒ t= 135.62 years.

Therefore 25 grams will be present in 135.62 years.

move it to the other side

step-by-step explanation: