Question

a radioactive sample contains 10,000 atoms. after two half-lives, how many atoms remain undecayed? a radioactive sample contains 10,000 atoms. after two half-lives, how many atoms remain undecayed? 10,000 7,500 5,000 2,500

Answer 1

Answer:

$\huge\boxed{\sf 2500\ atoms}$

Explanation:

Half Life:

• The time in which half of the radioactive substance decays is known as its half life.

Solution:

Atoms = 10,000

After 1st half life:

= 10,000 / 2

= 5,000 atoms

After 2nd half life:

= 5,000 / 2

= 2500 atoms

So, after 2 half lives, 2500 atoms remain.

$\rule[225]{225}{2}$