Mixtures cannot be separated by physical means are the same as compounds are always solutions are not chemically united and sand is made of different types of rocks. the shapes and sizes of the rocks are not all the same. sand is a compound solution mixture solute

why is arctic sea ice important? arctic sea ice keeps the polar regions cool and moderate global climate. sea ice has a bright surface; 80 percent of the sunlight that strikes it is reflected back into space. as sea ice melts in the summer, it exposes the dark ocean surface.

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."