The radioactive element carbon-14 has a half-life of 5750 years. A scientist determined that the bones from a mastodon had lost 67.6% of their carbon-14. How old were the bones at the time they were discovered?

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)

one negative thing it that it can kill water animals. another negative thing is it can cause the destruction of ecosystem. one way water pollution can be reduced is to conserve energy.