It is am example of a COMPOUND
Answer:
D) found in a limited time span
Explanation:
Index fossils are the remains of living organisms for which we have already established relative age. These are fossils that only existed during a limited period of geologic time and are easily identified, found in large volumes, and found in many different locations around Earth. Due to these factors, index fossils may be used as a guide for comparison in determining the relative age of an unknown object.
have a nice day and mark me brainliest! :)
1. add heat and components with lower boiling points will evaporate while heavier molecules will turn back into liquid
2. vapor reaching the top of the column is collected in an industrial condenser
3. substances remaining the the column continue the process