Give the symbols for 4 species that are isoelectronic with the Xe

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

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

How might this scientific phenomena be explained? a paper clip floats on water.