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

[stackrel(+3)"Al"stackrel(" "3 xx -2)("O"_3)]^(3-)
fits your description, which is remarkably unstable and would not exist. ${\text{AlO}}_{4}^{5 -}$ exists in ${\text{Na"_5"AlO}}_{4}$, an aluminate oxyanion, and "Al"("OH")_3 exists, aluminum hydroxide...
We can however have ${\text{Al"_2"O}}_{3}$, aluminum oxide, as $2 \times \left(+ 3\right) + 3 \times \left(- 2\right) = 0$, as required by conservation of charge.