5. What are the percentages of the two elements at three half-lives of potassium-40?

carbon

explanation:

not only is it colder, it also becomes darker, less salty, and more dense.

if you listed your answers right then i believe your answer is b.

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.