What are the big differences between physical and chemical properties?

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

Air can be considered a mixture. which statement does not explain why?

Show how to convert the temperature 84.7° c to kelvin. include all steps and label the final answer