Which of the following process requires the largest amount of energy ?

Options

A. `Al_((g))rarrAl^(o+) +e^(-)`
B. `Al_((g))^(2+)rarrAl^(3+)+e^(-)`
C. `Al_((g))^(o+) rarr Al^(2+) + e^(-)`
D. All require same amount of energy

Explanation

To determine which process requires the largest amount of energy, we need to analyze the given options in terms of ionization energy. Ionization energy is the energy required to remove an electron from an atom or ion in the gaseous state.

### Step-by-Step Solution:

1. **Identify the Processes**:
- Option A: Ammonium ion (NH4+) loses one electron to become NH4.
- Option B: Aluminum ion (Al2+) loses one electron to become Al3+.
- Option C: Aluminum ion (Al+) loses one electron to become Al2+.
- Option D: All processes require the same amount of energy.

2. **Understand Ionization Energies**:
- Ionization energy generally increases with the removal of successive electrons. This is because the remaining electrons are held more tightly by the nucleus as the positive charge increases when electrons are removed.

3. **Analyze Each Option**:
- **Option A**: This is the first ionization energy (IE1) for NH4+, which is relatively low.
- **Option B**: This represents the third ionization energy (IE3) for aluminum, which is higher than the first and second ionization energies due to the increased nuclear charge and decreased size of the ion.
- **Option C**: This is the second ionization energy (IE2) for aluminum, which is also higher than the first but lower than the third.
- **Option D**: States that all processes require the same energy, which is incorrect based on the trends in ionization energy.

4. **Compare the Ionization Energies**:
- Since successive ionization energies increase, we can conclude that IE3 (removing the third electron from Al2+) will require the most energy compared to IE1 (removing the first electron from NH4+) and IE2 (removing the second electron from Al).

5. **Conclusion**:
- The process that requires the largest amount of energy is **Option B**, where Al2+ loses one electron to become Al3+.

### Final Answer:
The process that requires the largest amount of energy is **Option B**.