For the second period elements the correct increasing order of first io0nization enthalpy is:

Options

A. `LiltBtltBltCltOltNltFltNe`
B. `LiltBeltBltCltNltOltFltNe`
C. `LigtBltBeltCltOltNltFltNe`
D. `LiltBltBeltCltNltOltFltNe`

Explanation

To determine the correct increasing order of first ionization enthalpy for the second period elements, we need to analyze the elements based on their electronic configurations and the stability of their valence electrons. The second period elements are:

1. Lithium (Li)
2. Beryllium (Be)
3. Boron (B)
4. Carbon (C)
5. Nitrogen (N)
6. Oxygen (O)
7. Fluorine (F)
8. Neon (Ne)

### Step-by-Step Solution:

**Step 1: Write the electronic configurations of the second period elements.**
- Lithium (Li): 1s² 2s¹
- Beryllium (Be): 1s² 2s²
- Boron (B): 1s² 2s² 2p¹
- Carbon (C): 1s² 2s² 2p²
- Nitrogen (N): 1s² 2s² 2p³
- Oxygen (O): 1s² 2s² 2p⁴
- Fluorine (F): 1s² 2s² 2p⁵
- Neon (Ne): 1s² 2s² 2p⁶

**Step 2: Analyze the stability of the valence electrons.**
- Fully filled (Neon) and half-filled (Nitrogen) orbitals are more stable than partially filled orbitals.
- Therefore, elements with fully filled or half-filled orbitals will have higher ionization energies.

**Step 3: Determine the order of ionization enthalpy based on stability.**
- Lithium has the lowest ionization enthalpy because it has only one electron in the 2s orbital, which is relatively easy to remove.
- Beryllium has a fully filled 2s orbital, making it harder to remove an electron compared to lithium.
- Boron has one electron in the 2p orbital, which is easier to remove than the fully filled 2s of beryllium.
- Carbon has two electrons in the 2p orbital, making it harder to remove an electron compared to boron.
- Nitrogen has a half-filled 2p orbital (2p³), which is relatively stable and thus has a higher ionization enthalpy than carbon.
- Oxygen has one more electron than nitrogen, making it easier to remove an electron compared to nitrogen.
- Fluorine has a high ionization enthalpy due to its high electronegativity and nearly full p orbital.
- Neon has the highest ionization enthalpy because it has a fully filled outer shell.

**Step 4: Write the final order of increasing ionization enthalpy.**
The correct increasing order of first ionization enthalpy is:
Li < B < Be < C < N < O < F < Ne

### Final Answer:
Li < B < Be < C < N < O < F < Ne