Question

multiple-choice question
when you change the subscript...
(choose all that apply)
nothing happens.
the molecule changes from water to peroxide.
the number of atoms changes.
the reaction changes.
rewatch

Explanation:

• Changing a subscript alters the chemical formula, so "nothing happens" is incorrect.
• For example, changing the subscript of oxygen in $\text{H}_2\text{O}$ (water) to 2 creates $\text{H}_2\text{O}_2$ (hydrogen peroxide), so the molecule can change from water to peroxide.
• Subscripts represent the number of each atom in a molecule, so modifying them changes the total number of atoms.
• Changing the molecule itself changes how it participates in chemical reactions, so the reaction changes.

Answer:

• the molecule changes from water to peroxide.
• the number of atoms changes.
• the reaction changes.