The high reactivity of fluorine is mainly due to

Answer

**Step-by-Step Solution:**

1. **Understanding Fluorine's Position in the Periodic Table:**
- Fluorine is located in Group 17 (VIIA) of the periodic table, which consists of halogens. These elements are known for their high reactivity.

2. **Atomic Number and Electronic Configuration:**
- Fluorine has an atomic number of 9. Its electronic configuration is 1s² 2s² 2p⁵. This configuration indicates that fluorine has 7 electrons in its outermost shell (2s and 2p orbitals).

3. **Electronegativity:**
- Fluorine is the most electronegative element, meaning it has a strong tendency to attract electrons. This high electronegativity is a key factor in its reactivity.

4. **Unpaired Electrons:**
- In its valence shell, fluorine has one unpaired electron (in the 2p orbital). This unpaired electron makes fluorine eager to gain one more electron to achieve a stable octet configuration (8 electrons in the outer shell).

5. **Tendency to Accept Electrons:**
- Due to its high electronegativity and the presence of an unpaired electron, fluorine readily accepts an electron from other elements during chemical reactions. This characteristic is what makes fluorine highly reactive.

6. **Conclusion:**
- The high reactivity of fluorine is mainly due to its high electronegativity and its ability to attract electrons to complete its octet.

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