Is corrosion garvanic or electrolytic?Why?

Define dew point. i am writing this part to be able to ask the question

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 neutrons does an element have if its atomic number is 50 and its mass number is 166