How does one recognize a periodic trend on the periodic table?
a. compare an element's properties to the properties of a noble gas.
b. look for predictable changes and patterns.
c. find elements in random positions of the periodic table.
d. look for all elements with two electrons in any orbital.

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 !