Which one of the following is a solution?

question 21 options:

oxygen

salt water

sugar

chocolate chip cookies

which of the following is a compound?
sugar

chocolate chip cookies

oxygen

salt water

why is water considered a pure substance and not a mixture?

question 23 options:

water can be separated physically into hydrogen and oxygen.

water is clear.

water can be separated chemically into hydrogen and oxygen.

water is not a pure substance. it is a mixture.

how can a mixture of pigments be separated?

question 24 options:

filtration

crystallization

magnetic attraction

chromatography

Hot air balloons float in the air because of the difference in density between cold and hot air. in this problem, you will estimate the minimum temperature the gas inside the balloon needs to be, for it to take off. to do this, use the following variables and make these assumptions: the combined weight of the pilot basket together with that of the balloon fabric and other equipment is w. the volume of the hot air inside the balloon when it is inflated is v. the absolute temperature of the hot air at the bottom of the balloon is th (where th> tc). the absolute temperature of the cold air outside the balloon is tc and its density is ďc. the balloon is open at the bottom, so that the pressure inside and outside the balloon is the same. as always, treat air as an ideal gas. use g for the magnitude of the acceleration due to gravity.

Hey guys so i need to know what is _nh3+> nh4oh ~chemistry~

The bone of a dinosaur and the imprint of a leaf are examples of which kind of fossils? a) index b) body c) amber d) trace