There are how many different crystal systems? ? a. 7 b. 9 c. 5 d. 2 f. 3 (( answer quick..this is for a quiz. the right answer will get the brainliest ))

What is the lowest number energy level where a d sublevel is found

Describe the forces both attractive and repulsive that occur as two atoms move closer together.

Need what is special about water as a compound? how does water regulate climate? what drives water evaporation?   why is the water vapor fresh water when it rises from the ocean? why might freshwater in the form of snow take longer to enter the water cycle again than liquid precipitation?   what is an aquifer? what role do people play in the water cycle? plz just answer as many as you can ! thx if you !