Which quantity helps determine the absolute age of rocks and fossils?(1 point) And why is that answer true?
Responses
the ratio of protons to neutrons in carbon-14
the ratio of protons to neutrons in carbon-14
the ratio of carbon-12 to carbon-14
the ratio of carbon-12 to carbon-14
the difference between the amounts of carbon-12 and carbon-14
the difference between the amounts of carbon-12 and carbon-14
the difference between the number of protons and neutrons in carbon-14
the difference between the number of protons and neutrons in carbon-14
This answer is true because the number of protons and neutrons in an isotope like carbon-14 determines its stability and rate of radioactive decay. By measuring the amount of carbon-14 remaining in a sample, scientists can calculate its age.
The correct answer is: the ratio of carbon-12 to carbon-14.
This is true because the ratio of carbon-12 to carbon-14 in a rock or fossil can be used to determine its absolute age. Carbon-14 is a radioactive isotope of carbon that is constantly formed in the atmosphere and taken in by living organisms through respiration or consumption of plants. However, once an organism dies, it no longer takes in new carbon-14, and the existing carbon-14 in its body begins to decay at a known rate. By comparing the ratio of carbon-12 (a stable isotope) to carbon-14 in a sample, scientists can determine how long it has been since the organism died and therefore determine the absolute age of the rock or fossil.
The correct answer is:
the ratio of carbon-12 to carbon-14
This ratio helps determine the absolute age of rocks and fossils because carbon-14 is an isotope of carbon that undergoes radioactive decay. Carbon-14 has a half-life of about 5730 years, which means that over time, half of the carbon-14 atoms in a sample will decay into nitrogen-14. By measuring the ratio of carbon-12 to carbon-14 in a sample, scientists can determine how long it has been since the organism that formed the fossil or rock died.
Since living organisms constantly take in carbon from the environment, the amount of carbon-12 in a sample remains relatively constant. However, the amount of carbon-14 decreases over time due to radioactive decay. By comparing the amount of carbon-12 to carbon-14 in a sample, scientists can calculate the age of the sample.
So, the ratio of carbon-12 to carbon-14 is an important tool in determining the absolute age of rocks and fossils.