Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.
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Question: Question: What cannot be created or destroyed in a chemical reaction? Answer: matter

Answer: Law stating that matter cannot be created or destroyed in chemical reactions.

Question: Question: What do scientists believe are the oldest eukaryotes? Answer: protists

Answer: Scientists think that protists are the oldest eukaryotes. They most likely evolved from prokaryotic cells, as explained by the endosymbiotic theory. This theory is well-supported by evidence.

Question: Question: Minerals are grouped based on what? Answer: chemical composition

Answer:
Minerals are divided into groups. The groups are based on their chemical composition.