The sigma bond for the in bonding orbital of hydrogen encompasses both H protons rather than the P-P sigma bond in F2. Also flurine has greater electronegetivity allowed less sharing of sigma bond keeping electron closer to respective nucleii.

**H-H Bond Energy**

The bond energy refers to the amount of energy required to break a specific type of bond in a chemical compound. The H-H bond energy is higher than the F-F bond energy due to several factors related to the nature of chemical bonding.

**Electronegativity Difference**

One of the key factors influencing bond energy is the difference in electronegativity between the two atoms involved in the bond. Electronegativity is a measure of an atom's ability to attract electrons towards itself. Fluorine (F) is the most electronegative element on the periodic table, whereas hydrogen (H) has a lower electronegativity.

**Polarity of the Bond**

The electronegativity difference between hydrogen and fluorine leads to the formation of a polar covalent bond in hydrogen fluoride (HF). In a polar covalent bond, the electrons are unequally shared between the atoms, resulting in the development of partial positive and partial negative charges. The polarity of the H-F bond increases the attraction between the atoms, making it stronger and more stable compared to the H-H bond.

**Size of the Atoms**

Another factor that affects bond energy is the size of the atoms involved. Fluorine atoms are significantly smaller than hydrogen atoms due to their higher effective nuclear charge and greater number of protons. The smaller size of fluorine atoms allows for a closer approach of the bonding electrons, resulting in a stronger attraction between the electrons and the nuclei. Consequently, the F-F bond is shorter and stronger than the H-H bond.

**Orbital Overlap**

The strength of a covalent bond also depends on the extent of orbital overlap between the bonding atoms. In the case of H-H bond, the overlap between the two s orbitals is less effective compared to the overlap between the H and F orbitals in the H-F bond. The greater overlap in the H-F bond leads to a stronger bonding interaction and higher bond energy.

**Conclusion**

In summary, the higher H-H bond energy compared to the F-F bond energy can be attributed to the difference in electronegativity, polarity of the bond, size of the atoms, and orbital overlap. These factors collectively contribute to the strength and stability of the H-H bond, making it stronger than the F-F bond.