Abiology teacher takes fish, algae, pond weed, invertebrates, and bottom muck from a local pond and establishes them in an aquarium. when the system is stable, the teacher seals it into a large, airtight glass box and leaves the box in a sunny location. after three months, the organisms in the aquarium appear alive and healthy. which of the following statements about the experiment is true? a. no energy has entered or left the glass box during the three months. b. during the three months, the biomass of animal life was greater than the biomass of plant life. c. some of the energy in the system has moved from one organism to another during the three months. d. the air in the glass box contains no carbon dioxide. e. some oxygen from water molecules has become part of organic molecules.

answer: carbon 14 can only be used to determine the age of the organisms that were once living, and igneous rocks are non living.

explanation:

carbon 14 dating is used to determine the age of the sample by estimating the amount of carbon 14 present in the sample and then comparing it with a reference standard.carbon 14 is a isotope of carbon which is radioactive and unstable. carbon 14 is assimilated by all plants and animals throughout their life from carbon dioxide. however, one the organisms die they stop this assimilation and the carbon 14 content starts to decrease.by knowing how much of carbon 14 is left in an organism after his death, one can estimate the age of the organism. the materials whose age can be estimated by carbon 14 method are the organic compounds. however, some inorganic compounds such as aragonite   shell can also be dated.however, if we consider the igneous rocks it is a non living component which never accumulated carbon 14 in it and thus, we cannot use carbon 14 dating method to estimate its age.

Country b may have shorter life expectancies. country a has more literate people. country a has better health care system. apex