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Needthe meter is the standard unit for: 1) height 2) length 3) weight 4) mass

List four observations that indicate that a chemical reaction may be taking place

Why does earth rotate? because earth is formed from cold gases collapsing due to gravity because the matter in the nebula that formed earth was spinning because earth forms more than 99% of the mass of the solar system because the hydrogen atoms inside the nebula fused to form helium