What must be true of the net charge for any sample of sodium chloride

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

Convert the temperature of dry ice, –77 ∞c, into degrees fahrenheit and kelvin.

What effect would average population growth have on land usage? a. urban use of land would rise to more than 30 percent of available land. b. industrial use of land would rise to more than 30 percent of available land. c. the percentage of available land used as cropland would stay the same. d. cropland would fall to about 10 percent of available land.