Pick all the characteristics below that describe compounds

two or more elements

chemically combined elements

one type of atom

cannot be separated into a simpler form

definite proportions

two or more elements

chemically combined elements

definite proportions

2020 on edge

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.