To determine the oxidation numbers of each atom in the given substances, we will follow standard rules for assigning oxidation states. Let's go through each substance one by one:
NF3
- N: +3 (Nitrogen is less electronegative than fluorine)
- F: -1 (Fluorine always has an oxidation state of -1)
K2CO3
- K: +1 (Potassium is an alkali metal, typically +1)
- C: +4 (In carbonate, C is typically +4)
- O: -2 (Oxygen usually has an oxidation state of -2)
HIO4
- H: +1 (Hydrogen is usually +1)
- I: +7 (For Iodine in peroxides due to 4 O's, resulting in +7 total to balance for -8 from O)
- O: -2 (Oxygen usually has an oxidation state of -2)
Br2
- Br: 0 (In elemental form, the oxidation state is 0)
2NaI
- Na: +1 (Sodium is an alkali metal, usually +1)
- I: -1 (Iodine in compounds is often -1, especially in ionic form like iodide)
I2
- I: 0 (In elemental form, the oxidation state is 0)
2NaBr
- Na: +1 (Sodium is an alkali metal, usually +1)
- Br: -1 (Bromine is typically -1 in ionic compounds)
Fe2O3
- Fe: +3 (Iron in this oxide is typically in the +3 state)
- O: -2 (Oxygen usually has an oxidation state of -2)
2Al
- Al: 0 (In elemental form, the oxidation state is 0)
Al2O3
- Al: +3 (Aluminum in this oxide is typically +3)
- O: -2 (Oxygen usually has an oxidation state of -2)
2Fe
- Fe: 0 (In elemental form, the oxidation state is 0)
Summary:
- NF3: N +3, F -1
- K2CO3: K +1, C +4, O -2
- HIO4: H +1, I +7, O -2
- Br2: Br 0
- 2NaI: Na +1, I -1
- I2: I 0
- 2NaBr: Na +1, Br -1
- Fe2O3: Fe +3, O -2
- 2Al: Al 0
- Al2O3: Al +3, O -2
- 2Fe: Fe 0
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