A.) desertification is when you remove all the trees and most of the plant life in an ares
60 elements! I don't exactly know every element known, so if you are asking that, please tell us, but what I do know is that there were 60 elements in the periodic table by 1860.
13.6
a) yes Pb is more reactive that Ag, Pb before Ag
b) no, Cu after H
c) yes, Cl2 is more active than I2
4) yes, Mg is more active
13.7 (as I think)
Al ³⁺ more active than Zn²⁺, Mn can react with Zn²⁺, but not with Al ³⁺ , because Mn after Al but before Zn
