4 An archeologist has found an ancient seashell that contain

4)         An archeologist has found an ancient seashell that contains 60% of the carbon-14 of a        living seashell. How old is the ancient seashell? [Hint: Carbon-14 is a radioactive isotope     of the common carbon-12 atoms. Carbon-14 is unstable and has a half-life of 5568 years.]

Solution

Since carbon-14 has a half-life of 5568 years I.e., 2784 years. Ancient seashell contains 60% of carnon-14 of a living seashell. Which implies that age of ancient seashell is equal to 60% times age of carbon-14

= 60%*2784

= 1670.4 years

Age of ancient seashell =1670.4 years old