Final answer:
The correct ordering for assigning oxidation states is: 'Free element > Monatomic ion > Group 1A and 2A > O > H'. This is because free elements always have an oxidation state of zero,
Step-by-step explanation:
Understanding the rules for assigning oxidation states is essential in chemistry, especially for balancing redox reactions. Here are the summarized key points:
- For free elements (uncombined state), including diatomic species, the oxidation state is always zero.
- Monatomic ions have oxidation states equal to their ionic charge.
- In compounds, Group 1A elements exhibit a +1 oxidation state, while Group 2A elements have a +2 oxidation state.
- Hydrogen, typically has an oxidation state of +1 when bound to nonmetals and -1 when bound to metals.
- Oxygen usually has an oxidation state of -2 in compounds, except in peroxides (-1) and when bonded to fluorine (varies).
When you arrange these by priority in assigning oxidation states: H > O > Group 1A and 2A > Monatomic ion > Free element, the correct option that follows the order of assigning oxidation numbers is 'b.
Free element > Monatomic ion > Group 1A and 2A > O > H' since free elements have the lowest priority (are always zero), followed by monatomic ions (equal to their charge), then by Group 1A and Group 2A elements, continuing with Oxygen (usually -2), and Hydrogen (usually +1).