In 1985, during the construction of a skyscraper in Austin, Texas, the remains of a mastodon were unearthed. If only 1/64 of the original carbon-14 remained, and carbon-14 has a half life of 5730 years, approximately how old were the mastodon bones?

Explanation:

The remaining amount of a radioactive isotope is found as the product of the original amount by (1/2) raised to the number of half-lives elapsed. The formla is:

Where M is the remaining amoun, M₀ i s the initial amount, and n is the number of half-lives.

Here, 1/64 of the original carbon-14 remained, meaning that M/M₀ = 1/64.

Then, you can substitute in the equation and solve:

Then, 6 half-lives elapsed since the mastodon died and the remains were dated.

Then, you must multiply 6 by the half-life time:

colorectal cancer may also develop from areas of abnormal cells in the lining of the colon or rectum. this area of abnormal cells is called dysplasia and is more commonly seen in people with certain inflammatory diseases of the bowel such as crohn's disease or ulcerative colitis.