When you buy isopropanol, commonly known as rubbing alcohol, it is a dilution. What volume of isopropanol is in 250 mL of a 70% solution?

An electron moved from shell n = 2 to shell n = 1. what most likely happened during the transition? a fraction of a photon was added. a photon of energy was absorbed. a fraction of a photon was removed. a photon of energy was released.

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.

How many moles of water are created if 3 moles of hydrogen react completely with excess oxygen?