Question

Explain how archeologists and geologists are able to use radioactive isotopes to determine the age of fossils and rocks.

Which term refers to the material that permits the transmission of energy through vibrations? a. elastic b. medium c. linear density d. compression

thank you so much

Answer 1

a) Isotope of an element that are radioactive are called its radioisotopes. They find several applications such as in the dating of archaeological samples and rocks.Radiocarbon dating or C-14 dating is a technique used for determining the age of archaeological carbonaceous objects (such as rocks and animal fossils) by measuring the radioactivity of 14C present in them.

In the atmosphere radiocarbon(14C) is formed by the bombardment of nitrogen by neutrons produced by cosmic rays. Any radiocarbon thus produced will soon be converted into radiocarbondioxide(14CO2) eventualy taken up along with normal carbon dioxide by green plants during photosynthesis. Plants are eaten up by animals and so a part of radio carbon gets into their systems.Further radiocarbon undergoes beta decay.when the animal dies further intake of radiocarbon stops. However radiocarbon already assimilated by it continues to undergo beta decay.As a result the radio carbon content of the dead sample gradually decrease . Hence by measuring its radio carbon activity its age can be calculated .

b). medium

Medium is the material that permits the transmission of energy through vibration . That can be solid liquid or gas