Some isotopes, however, decay slowly, and several of these are used as geologic clocks. Dating rocks by these radioactive timekeepers is simple in theory, but the laboratory procedures are complex. <span>All methods rely on the fact that certain elements (particularly uranium and potassium) contain a number of different isotopes whose half-life is exactly known and therefore the relative concentrations of these isotopes within a rock or mineral can measure the age.</span>
Answer:
A. Nuclear reactors increase thermal pollution
Explanation:
From the analogy provided in this context, we can vividly see that the author is suggesting that the use of nuclear energy causes thermal pollution.
- Nuclear energy is an alternate energy source as identified in the text.
- Since a huge amount of heat energy is generated and they are not all used up, they are released into the ecosystem.
- The earth is usually depicted as heat reservoir.
- Increased release of heat to the environment will cause thermal pollution.
- This increases the ambient temperature of water and degrades it.
<u>Answer</u>: a. This represents the requirements for the highest quality scientific methodology.
This question is part of the problem solving value rubric created by the AACU (The Association of American College and Universities). The number 4 represents the score assigned to the experimental design and the text illustrates the requirements needed to reach it.
a - is the highest score - the capstone
b&c - the milestones
d - the benchmark - the minimum score needed to pass.
Anything lower than the benchmark will be assigned a 0 and failed.
