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Multiple Choice
Which of the following is the correct formula for the ionic compound formed between aluminum and oxygen?
A
Al2O3
B
AlO2
C
AlO
D
Al3O2
Verified step by step guidance
1
Identify the charges of the ions formed by aluminum and oxygen. Aluminum typically forms a +3 charge (Al^{3+}), and oxygen typically forms a -2 charge (O^{2-}).
Determine the ratio of aluminum ions to oxygen ions needed to balance the total positive and negative charges so that the compound is electrically neutral.
Set up the equation to balance charges: (number of Al ions) \times (+3) + (number of O ions) \times (-2) = 0.
Find the smallest whole number ratio of Al to O that satisfies the charge balance. This involves finding the least common multiple of the charges 3 and 2, which is 6.
Write the formula using the ratio found: since 2 Al^{3+} ions contribute +6 charge and 3 O^{2-} ions contribute -6 charge, the formula is Al_{2}O_{3}.