The answer would be D because from my research it's the only one that didn't have a catalyst
Most transition metal form more than one cation but aluminum forms the Al3+ cation only.
You have to think about the fact that hot air is constantly being blown up elevating the balloon once that air is taken away it's up to the steering and the wind after that. I know that probably doesn't help did you want to know the science part?
Copper. thats the way copper oxidized. like the statue of liberty
