7) magnesium consists of three naturally occurring isotopes. the percent abundance of
these isotopes is as follows: "mg (78.70%), mg (10.13%), and "mg (11.7%). the average
iss of the three isotopes is 24.3050 amu. if the atomic mass of -mg is 24.98584
amu, and mg is 25.98259 amu, calculate the actual atomic mass of mg.

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

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 !

Which radioisotope is used to date fossils? a. oxygen-16 b. carbon-14 c. uranium-238 d. carbon-12