Answer:In the chemical formula Al2(SO4)3, the Al2 means there two aluminium (atoms or ions). The SO4 is a sulfate ion and (SO4)3 means there are 3 sulfate ions. The number 3 before Al2(SO4)3 means there are three times the number of atoms and ions of the chemical formula.
0.000345 in scientific notation is 3.45*10^-4
Greenhouse effect/climate change
Plant and crop life
Human and animal health
Oceans
None of them really sound like the answer, but my best guess would probably be the second one. It doesnt give much info.
