If a sample that originally contain 10 grams of C14 has gone through two half-lives of Decay how much C14 will be left?

Answer 1

2.5

Answer 2

Yes it is used for this.

Any radioactive isotope decays with time into something else (another element) the time it take for 1/2 of it to have decayed to this other element is called its half life.

If one knows how much of this radioactive material was present initially in the object (by determining how much of the material has decayed), and one knows the half-life of the material, one can deduce the age of the object.

For instance the decay of 238U to 206Pb, has a half-life of 4.46 billion years and the decay of 235U to 207Pb, has a half-life of 704 million years and this allows you to measure the age of the planet itself.

Answer 3

2.5 grams of C14 would be left after two half-lives.

Answer 4

10 g of activity will decay to 2.5 g after 2 half-lives.

AN = A0 2(-N/H) where N is half-lives, A is activity, and H is half-life.

Answer 5

After one half live, there will be 5 grams left. And after 2 half lives, there will be 2.5 grams left.

Answer 6

After two half-lives of C-14 decay, only 25% of the original C-14 will remain. This means that 2.5 grams of C-14 will be left out of the original 10 grams.

Answer 7

4