Which of the following cations of Mn will have highest ionization energy?

Options

A. `Mn^(+2)`
B. `Mn^(+4)`
C. `Mn^(+6)`
D. `Mn^(+7)`

Answer

To determine which cation of manganese (Mn) has the highest ionization energy, we can follow these steps:

### Step 1: Understand Ionization Energy
Ionization energy is defined as the minimum energy required to remove the most loosely bound electron from an isolated neutral gaseous atom or molecule. The higher the ionization energy, the more energy is needed to remove an electron.

**Hint:** Remember that ionization energy increases with the effective nuclear charge experienced by the electrons.

### Step 2: Consider the Charge of the Cations
The cations of manganese we need to consider are Mn²⁺, Mn³⁺, Mn⁴⁺, and Mn⁷⁺. The charge on the cation affects the effective nuclear charge, which in turn influences the ionization energy.

**Hint:** More positive charge on the cation means a higher effective nuclear charge.

### Step 3: Analyze the Cations
- **Mn²⁺**: Has a charge of +2.
- **Mn³⁺**: Has a charge of +3.
- **Mn⁴⁺**: Has a charge of +4.
- **Mn⁷⁺**: Has a charge of +7.

As the charge increases, the effective nuclear charge experienced by the outermost electrons also increases.

**Hint:** Compare the charges to see which one is the highest.

### Step 4: Determine the Highest Ionization Energy
Among the given cations, Mn⁷⁺ has the highest charge (+7). This means it will exert the strongest pull on its electrons due to the high effective nuclear charge, making it the most difficult to remove an electron from.

**Hint:** The cation with the highest charge will have the highest ionization energy.

### Step 5: Conclusion
Therefore, the cation of manganese that will have the highest ionization energy is **Mn⁷⁺**.

**Final Answer:** Mn⁷⁺ has the highest ionization energy.