Final answer:
The oxidation states for H₂O are +1 for hydrogen and -2 for oxygen, for SO₃ it's +6 for sulfur, for NO₂ it's +4 for nitrogen, and for NH₄⁺ it's -3 for nitrogen.
Step-by-step explanation:
To determine the oxidation states of the elements in a compound, we can use a set of rules.
The compounds you've listed can have their oxidation states found as follows:
- H₂O: Hydrogen is typically +1, and oxygen is typically -2. Since there are two hydrogens, the total oxidation number for hydrogen is +2, which balances the -2 for the single oxygen.
- SO₃: Oxygen is usually -2, and since there are three oxygens, their total is -6. Therefore, sulfur must be +6 to balance this out.
- NO₂: Oxygen is -2 each, and with two oxygens this gives -4, so nitrogen must be +4 to have a neutral compound.
- NH₄⁺: Again, hydrogen is +1, and with four hydrogens, it's +4. Since the ion overall has a charge of +1, that means nitrogen is -3 to balance the charge.