The Bond Type and Structure of HF
Hydrogen fluoride is a polar covalently bonded molecule consisting of one hydrogen atom and one atom of fluorine. Hydrogen's electronegativity number is 2.1 and fluorine's is 4.0, meaning the bond is very polar and nearly ionic. Because of this, the area around the fluorine atom has a slight negative charge, while the area around the hydrogen has a slight positive one. When multiple HF molecules combine together, they form orthorhombic crystals, with zig-zag chains of the molecules as shown in the banner picture above. When HF exists as a liquid, the chains of molecules are shorter, usually containing only five or six molecules.
Structure Video of Covalent Bonds
The following is a video describing the structure of covalent bonds, including the bond between hydrogen and fluorine atoms in our molecule.