Which of the following formula representation is NOT correct?

Options

A. `H_(2)O`
B. `Na_(2)CO_(3)`
C. `Fe_(2)(SO_(4))_(3)`
D. `Mg_(2)O_(2)`

Answer

To determine which of the given formula representations is NOT correct, we will analyze each option step by step.

### Step 1: Evaluate H2O
- **Formula:** H2O
- **Analysis:** This is the chemical formula for water, which consists of two hydrogen atoms and one oxygen atom.
- **Conclusion:** This representation is correct.

### Step 2: Evaluate Na2CO3
- **Formula:** Na2CO3
- **Analysis:** This is the chemical formula for sodium carbonate, which consists of two sodium atoms, one carbon atom, and three oxygen atoms.
- **Conclusion:** This representation is correct.

### Step 3: Evaluate Fe2SO4-3
- **Formula:** Fe2SO4-3
- **Analysis:** The correct formula for ferric sulfate is Fe2(SO4)3, indicating that there are two iron atoms and three sulfate ions. The way it is presented here might be misleading, but it can be interpreted as correct if we consider the context.
- **Conclusion:** This representation can be considered correct, though it is not the standard way to write it.

### Step 4: Evaluate Mg2O2
- **Formula:** Mg2O2
- **Analysis:** Magnesium oxide is typically represented as MgO. The valency of magnesium is +2, and the valency of oxygen is -2. Therefore, the correct formula should reduce to MgO, not Mg2O2.
- **Conclusion:** This representation is incorrect.

### Final Conclusion
The formula representation that is NOT correct is **Mg2O2**.

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