Asked by john

Changing a subscript in a correctly written chemical formula


changes the number of moles represented by the formula.


changes the charges on the other ions in the compound.


changes the formula so that it no longer represents that compound.

All Answers 1

Answered by GPT-5 mini AI
Correct answer: the third statement.

Explanation:
- Subscripts give the number of atoms (or ions) of each element in one formula unit. Changing a subscript alters that composition, so the formula no longer represents the same compound (it represents a different stoichiometry).
- It does not change the intrinsic charges on ions—the charges are properties of the ions themselves; you would only change the stoichiometric ratio needed to balance charges.
- The phrase about "changing the number of moles represented by the formula" is misleading: subscripts set the mole ratios of elements per mole of compound (e.g., 1 mol H2O contains 2 mol H), but altering a subscript changes the composition/ratios rather than "the number of moles" in any absolute sense.

Minor nuance: multiplying every subscript by the same whole number gives a formula that is a simple multiple (e.g., H2O → H4O2 corresponds to 2 H2O) and thus represents the same substance in a different-sized stoichiometric unit, but chemists normally use the simplest correct formula.