After an organism dies, it stops taking in radioactive carbon-14 from the environment. If the carbon-14:carbon-12 ratio ( / ) in a piece of petrified wood is one sixteenth of the ratio in living matter, how old is the rock

Age of rock= 22920 years

Explanation:

Carbon-12 isotope is a stable isotope whereas carbon-14 isotope undergoes radioactive decay. The half-life of carbon-14 isotope = 5730 years

Since the ratio of carbon-14 to carbon-12 = 1/16 : 1; number of times carbon-14 isotope decayed n

(1/2)ⁿ = 1/16

(1/2)ⁿ = (1/2)⁴

n = 4 times

time(age) for decay = n * half-life

Therefore, age of fossil = 4 * 5730 years

Age of rock = 22920 years

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation: