Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Dipole-dipole interactions are the only non-covalent interactions, resulting in hydrogen bond formation.
Reason R: Fluorine is the most electronegative element and hydrogen bonds in HF are symmetrical.
In the light of the above statements, choose the most appropriate answer from the options given below:

Assertion A states: "Dipole-dipole interactions are the only non-covalent interactions, resulting in hydrogen bond formation." This assertion is false. Hydrogen bonding is not solely due to dipole-dipole interactions. Modern understanding shows that hydrogen bonds have multiple components: (i) electrostatic attraction between the partial positive charge on H and the lone pair of the electronegative atom, (ii) charge-transfer or partial covalent character due to overlap of the lone pair orbital with the antibonding $$\sigma^*$$ orbital of the X-H bond, and (iii) dispersion forces. Therefore, attributing hydrogen bonding exclusively to dipole-dipole interactions is incorrect.

Reason R states: "Fluorine is the most electronegative element and hydrogen bonds in HF are symmetrical." The first part is true — fluorine has the highest electronegativity (3.98 on the Pauling scale). The second part refers to the bifluoride ion $$[F \cdots H \cdots F]^-$$, in which the proton sits symmetrically between the two fluorine atoms at equal distances. This symmetric hydrogen bond is well-documented and is one of the strongest known hydrogen bonds. Thus, Reason R is true.

Since Assertion A is false and Reason R is true, the correct answer is: **A is false but R is true**.