<span>Species is a group of reproducing populations that are isolated from other groups. </span>
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:
Because the Arctic glacier is crucial in cooling the land.
Explanation:
The glaciers contained in the Arctic are essential for cooling the earth's climate, which is why Arctic conditions are so important in determining the earth's climate changes.
These glaciers reflect about 80% of the sunlight in the northern hemisphere, and can cool the region's climate. If Arctic glaciers melt, most of the sun's rays will be absorbed by the ocean, increase the temperature and increase the melting of the glaciers.
As a result, the entire ecosystem will be damaged.
