1 point
Carbon dating uses an isotope of the element carbon. The most common
form of carbon has 6 protons and 6 neutrons. It is called carbon-12.
Carbon-14 is an isotope of carbon that has 8 neutrons. The extra neutrons
make carbon-14 unstable, or radioactive. Atoms that are unstable tend to
break apart. This process is called radioactive decay. All living organisms
contain carbon. Plants get carbon from the atmosphere. Animals get
carbon from food. Most of the carbon is carbon-12, but some of it is
carbon-14. Carbon cycles through living things while they are alive. The
ratio of carbon-12 to carbon-14 remains the same while a plant or animal is
alive. When the plant or animal dies, the carbon-14 begins to decay. By
comparing the ratio of carbon-12 to carbon-14, scientists can tell how long
the plant or animal has been dead. To determine the absolute age of rocks
and fossils, scientists use: *
O The difference between the amounts of carbon-12 and carbon-14.
O The ratio between carbon-12 and carbon-14
O The difference between the number of protons and neutrons in carbon-14.