Which of these is an example of a chemical change? a. dissolving salt in water b. melting ice c. burning a piece of wood d. breaking a tree branch

Your answer is probably ether A.Dissolving salt in water. or C.Burning a piece of wood.

answer: that would be cheating

explanation:

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.