Question

question 14 of 20 :
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1. regarding the formula al₂o₃ which of the following is accurate?

a. the coefficient 3 indicates that there are a total of three atoms of oxygen present in the substance.
b. the chemical symbol al indicates that argon is present in the substance.
c. the subscript 2 indicates that two atoms of oxygen are present in the substance.
d. the subscript 2 indicates that two atoms of aluminum are present in the substance.
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Explanation:

• Option A: In \( \text{Al}_2\text{O}_3 \), the subscript 3 means there are 3 O atoms per formula unit, not a "coefficient" (coefficients are for balanced equations, subscripts for formula units). So A is wrong.
• Option B: \( \text{Al} \) is aluminum, not argon (Ar). So B is wrong.
• Option C: The subscript 2 is for Al, not O. The subscript 3 is for O. So C is wrong.
• Option D: The subscript 2 next to Al in \( \text{Al}_2\text{O}_3 \) means there are 2 Al atoms per formula unit. This is correct.

Answer:

D. The subscript 2 indicates that two atoms of aluminum are present in the substance.