Why does matter (or the mass that makes it up) never "go away?"

0.09 moles of sodium sulfate in 12 ml of solution

How hot is the suns corona? (integrated science)

According to the valence shell electron pair repulsion (vsepr) theory, a molecule that has four electron groups around the central atom will exhibit what electron geometry? view available hint(s) according to the valence shell electron pair repulsion (vsepr) theory, a molecule that has four electron groups around the central atom will exhibit what electron geometry? trigonal bipyramidal tetrahedral square planar determination of electron geometry requires information on whether the electron groups are lone pairs or bonding groups.