<span><u>How does fossilized carbon get back into the atmosphere?</u>
</span>Fossilized carbon is coal. One major way it gets back into the atmosphere is by humans burning it in coal power plants. Carbon gets back into the atmosphere as carbon dioxide through the combustion of fossil fuels.
<span><span><u>How does a plant get nitrogen from the soil?</u>
</span></span>Plants take nitrogen from the soil<span> by absorption through their roots as amino acids, nitrate ions, nitrite ions, or ammonium ions.</span><span>
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<span>The Calvary is a work by Cheri Samba, an African artist who represented works of painting with themes of the reality of life in Africa, such as life, routine, economic problems and society in general. The Calvary is one of his most famous works and contains some violence because it represents images of pain and anguish in each stroke leaving traces and accounts of the feelings found in his works.</span>
The half-life of Carbon-14 is 5760 years.
<span>For carbon-14 to have decayed down by a factor of 12, we know between 3 and 4 half-lives must have elapsed. Since 4 half-lives is only 23,000 years, the sample is considerably younger than a dinosaur bone. (Unless we assume it's been contaminated with modern carbon, in which case, any age calculation based on carbon-14 is worthless.) </span>
<span>The decay equation is y = ae^(-0.0856t) with t in days. </span>
<span>To find the half-life, we solve for t such that y/a = 0.5. </span>
<span>0.5 = e^(-0.0856t) </span>
<span>Take natural logs of both sides: </span>
<span>-ln(2) = -0.0856t </span>
<span>-0.6931 = -0.0856t </span>
<span>Divide both sides by -0.0856... </span>
<span>8.096 = t </span>
<span>The half-life is 8.096 days.</span>
