AP BIOLOGY

Detailed explanation-1: -In the molecule HF, the electronegativity of the hydrogen is 2.2 and fluorine is 4.0. This difference leads to the profound polarization of the HF covalent bond which is apparent in the electrostatic potential map. Polarizations of covalent bonds also occur in more complex molecules.

Detailed explanation-2: -Hydrogen fluoride (HF) is a very polar molecule due to the large difference in electronegativity of hydrogen and fluorine atoms. This results in an induced positive charge on the hydrogen atom and a negative charge on the fluorine atom, creating a net dipole moment.

Detailed explanation-3: -For example, the H and F atoms in HF have an electronegativity difference of 1.9, and the N and H atoms in NH3 a difference of 0.9, yet both of these compounds form bonds that are considered polar covalent.

Detailed explanation-4: -Why is polar while, and are not polar? In and molecule, the two Hydrogen and two Fluorine atoms have same electronegativity. Hence, these molecules are non-polar in nature. In case of molecule, Fluorine atom is more electronegative than Hydrogen due to its small .

Detailed explanation-5: -(B) The H-F bond is more polar than the H-I bond because fluorine is more electronegative than iodine.