In the reaction Zn H 2SO 4→ ZNSO4 + H2, which, if any element is oxidized

What is the independent variable in this investigation? mass volume sample number substance density

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

About 3% of the water on earth is freshest. only about 40% of that freshwater is available for human use. why is so much freshwater unavailable for human use?