Answer:
A quarter of the sample.
Explanation:
Let the quantity at the beginning be T. If the element has a half-life of 1,000 years, it means that after 1000 years, T/2 (which represents half the initial quantity available) would have decayed, remaining T/2.
After another 1000 years (making 2000 years), T/4 (which represents have of the quantity left after the first 1000 years) would have decayed, remaining T/4.
This means that only a quarter of T would be left after 2000 years.
The answer is A, because the phytoplankton is the foundation of this food web. Without your foundation, "the building will begin to crumble".
I'd say D but i'm not 100% sure
<span>Thymine Is 20% in the DNA molecule.
Hope this helps.
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