What is a solution? are all mixtures solutions? are all solutions mixtures?

Part of molten rock at mid-ocean ridges

Which function is performed by earths atmosphere? a. ultraviolet rays are prevented from reaching the ozone layer. b. earths temperature is raised and moderated by trapping in heat c. charged particles from the sun are prevented from reaching earth. d. magnetic charges from space are prevented from reaching earths surface.

Complete the sentence. the lower the hydrogen ion concentration, the the ph. higher lower closer to 7 closer to 0