Answer:
I'm pretty sure the first one is c. The second one is b.
Explanation:
The decay of uranium isotopes is used to provide information about the age of Earth.
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Explanation:</h3>
Isotopes of Uranium U-232, U-233 , U-234 , U-235 , U-236 , U-238 are used as fuel in nuclear reactors or as explosives for nuclear weapons. Uranium 238 is not very radioactive and it constitutes for nearly 99.3% of natural uranium on Earth and has the longest lifetime: its period is 4.5 billion years, about the age of Earth.
Use of radiometric dating techniques help in defining the age of substances (natural or man-made) using the known decay rates of radioactive elements. Each element has an individual decay rate and half life time.
Two Uranium isotopes (U-238 and U-235) are used for radiometric dating. Both the isotopes have different decay rates and half life period. Both are unstable and radioactive. Since two different isotopes produce two different decay clocks (one as a reference to other), it is beneficial in accurately determining the age of samples. The age of earth (rocks or other natural elements) can be easily determined using Uranium isotopes.
Explanation:
In a food chain, only 10% of energy is transferred from one trophic level to another trophic level. If the energy produced at the producer level is 1000 J, then the energy available at the primary consumer level will be 100 J and energy available at the secondary consumer level will be 10 J.
Answer:
intrinsic
Explanation:
Proteins are dynamic molecules that are capable of INTRINSIC motion that can have important functional relevance. The existence of this type of motion has suggested that enzymes are capable - even in the absence of substrate - of many of the same movements that can be detected during their catalytic cycle