Compare and contrast the following chemical bonds: covalent bonds, ionic bonds, hydrogen bonds.
All these types of bonds, covalent, ionic and hydrogen bonds are molecular bonds. But covalent bonds and ionic bonds are both intramolecular bonds and hydrogen is a type of intermolecular bonds.
Covalent bonds are in between two atoms and occurred after sharing two electrons in their outer orbitals, thus completing the number of electrons in both their orbitals. When two atoms with less difference in electronegativity combines, covalent bonds are made.
In contrast ionic bonds are made when one atom gives an electron or more to the most electronegative atom. This makes one atom positive and other negative. They both make their outer electron shells complete, one by adding the required number of electrons and other by removing the outer shell. The attraction between the two opposite charges make the bond in ionic bonds. This usually happens when a metal reacts with halides or other non metal. Example: NaCl. Here Cl is more electronegative and it takes an electron from Na and make Na+ and Cl-. Ionic bonds are much stronger than covalent bonds.
Hydrogen bonds are totally different to both covalent bonds and ionic bonds. Hydrogen bonds are intermolecular bonds, that means they occur in between two molecules. They doesn't contribute to making a new molecule. Hydrogen bonds exist when H atom is bonded to a more electronegative atom and when that H atom is near a more electronegative atom in another molecule. But the atoms that contribute to Hydrogen bonds are O, N and F as they are the most electronegative atoms. When H atom is close to O,F, N atoms those atoms can attract H atoms electrons temporarily, thus making a weak bond. The typical molecules which show Hydrogen bonds are H2O, Ethanol, HF, Ammonia.