How many grams of NaHCO3 must be added to 4.0g of K2CO3 to give a pH of 10.80 in 500mL of water?

What is the standard unit of measure for acceleration?

The equation picture below shows which type of nuclear reaction u 235 + n x e 134 + sr 100 + 2n

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 !