alleryStart learning →What does the chemical formula of an ionic compound actually tell you?
AThe exact count of ions in one crystal
BThe simplest ratio balancing the charges
CThe shape adopted by a single molecule
DThe order in which the ions were added
Answer & Solution
Correct answer: B. The simplest ratio balancing the charges
1. Every substance must be electrically neutral overall, so positive and negative charges have to balance.
2. The formula records the simplest whole number ratio of ions that achieves that balance.
3. A real crystal holds an enormous number of ions, so the formula is never a headcount.
4. Nor does it describe a molecule, since an ionic solid contains no discrete molecules to shape.
_Source: OpenStax Chemistry (CC BY 4.0), Ch 7 "Chemical Bonding and Molecular Geometry", section The Formation of Ionic Compounds_
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