The element which has highest `II^(nd)` I.E. ?

Options

A. Li
B. Be
C. K
D. B

Answer

To determine the element with the highest second ionization energy (I.E.), we will follow these steps:

### Step 1: Understand Ionization Energy
Ionization energy is the energy required to remove an electron from an atom. The first ionization energy (I.E.1) is for removing the first electron, while the second ionization energy (I.E.2) is for removing the second electron.

### Step 2: Analyze the Given Elements
We need to analyze the elements given in the options. Let's consider the following elements:
- Lithium (Li)
- Beryllium (Be)
- Potassium (K)
- Boron (B)

### Step 3: Determine Electron Configurations After First Ionization
After the first ionization, the electron configurations of the ions formed are:
- Li → Li⁺: 1s² (2 electrons left)
- Be → Be⁺: 1s² (2 electrons left)
- K → K⁺: [Ar] (18 electrons left)
- B → B⁺: 1s² 2s² 2p⁴ (4 electrons left)

### Step 4: Identify Stability After First Ionization
After losing one electron:
- Li⁺ has a stable configuration (1s²).
- Be⁺ also has a stable configuration (1s²).
- K⁺ has a stable configuration ([Ar]).
- B⁺ is not stable as it still has electrons in the p-orbital.

### Step 5: Evaluate Second Ionization Energy
The second ionization energy will be highest for the element that, after losing its second electron, achieves a stable electron configuration.
- For Li⁺, removing another electron would lead to a configuration of 1s¹, which is not stable.
- For Be⁺, removing another electron leads to a configuration of 1s¹, which is also not stable.
- For K⁺, removing another electron leads to a configuration of [Ar] 3s², which is stable.
- For B⁺, removing another electron leads to a configuration of 1s² 2s² 2p³, which is not stable.

### Step 6: Conclusion
The highest second ionization energy will be for the element that is most stable after losing its second electron. In this case, Beryllium (Be) has the highest second ionization energy because it requires more energy to remove an electron from a stable 1s² configuration.

### Final Answer
The element with the highest second ionization energy is **Beryllium (Be)**.

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