Which of the following is not one of the three processes that were most intense during the first few hundred thousand years of the earths history?? Radioactive decay of unstable isotopes cooling of the mantle extraterrestrial impacts gravitational contraction of the earths interior

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explanation:

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.