Whicj of the following ions would represent the ion of an element from group 2a

What is the overall order of reaction for rate = k[no]2[o2]

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 !

You wish to prepare a buffer consisting of acetic acid and sodium acetate with a total acetic acetate plus acetate concentration of 250 mm and a ph of 5. what concentrations of acetic acid and sodium acetate should you use