Question

The half-life of a radioactive substance is 200 years. There are 8000 grams of the substance initially. How many grams of the substance are left after 300 years?

Answer 1

There are 2,000 grams left after 300 years.

Explanation:

Giving the following information:

The half-life of a radioactive substance is 200 years. There are 8000 grams of the substance initially.

First, we need to calculate the reduction of the substance each year:

Yearly reduction= 8,000/400= 20 grams per year

Now, for 300 years:

300 year reduction= 20*300= 6,000

There are 2,000 grams left after 300 years.