Question

What is the name of the compound that has one aluminum atom and three oxygen atoms?

Answer 1

There is none, because this compound doesn't exist.

`[stackrel(+3)"Al"stackrel(" "3 xx -2)("O"_3)]^(3-)`

fits your description, which is remarkably unstable and would not exist. `"AlO"_4^(5-)` exists in `"Na"_5"AlO"_4`, an aluminate oxyanion, and `"Al"("OH")_3` exists, aluminum hydroxide...

We can however have `"Al"_2"O"_3`, aluminum oxide, as `2 xx (+3) + 3 xx (-2) = 0`, as required by conservation of charge.