rusting of iron is a chemical change because it is two substances reacting together to make a new substance. When iron rusts, iron molecules react with oxygen molecules to make a compound called iron oxide. Rusting would only be a physical change if iron molecules remained pure iron throughout the process.
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Answer: They use enzymes.
Explanation:
Cells employ enzymes to drive and speed up their chemical reactions without being used up themselves. They are the only macromolecular biological catalysts that can start a reaction using the smallest available heat energy, thus overcoming the issue of needing high activation energy. Enzymes work by converting specific substrates to required product by binding them to their active site.
Answer:
abiotic factors refer to non-living physical and chemical elements in the ecosystem like water, air and sunlight.
biotic factors are living ot once-living organisms in the ecosystem like humans and animals
basically biotic is alive and abiotic is not alive