if an element X with atomic number 13 combines with an element Y whose atomic number is 8 the most likely formula of the compound formed between X and Y is?
XY
X2Y
XY2
X3Y2
X2Y3
Correct answer is E
Element X is aluminum of valency 3+
Element Y is oxygen of valency 2-
Their combination is \(Al_{2}O_{3}\)