Final answer:
Atomic orbitals and molecular orbitals describe the behavior of electrons around individual atoms and in molecules, respectively. Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons. Resonance and isomerism are related to the arrangement of atoms within molecules. Sigma bonds result from head-on overlap of atomic orbitals, while pi bonds result from side-by-side overlap of parallel p orbitals.
Step-by-step explanation:
Atomic orbitals and molecular orbitals: Both atomic and molecular orbitals are quantum-mechanical constructs that represent the probability of finding an electron. However, atomic orbitals describe the behavior of electrons around an individual atom, while molecular orbitals describe the behavior of electrons in a molecule formed by the combination of atomic orbitals.
Ionic and covalent bonds: Both ionic and covalent bonds are types of chemical bonds that hold atoms together. In ionic bonds, electrons are transferred from one atom to another, resulting in the formation of ions. In covalent bonds, electrons are shared between atoms.
Resonance and isomerism: Resonance and isomerism are concepts related to the arrangement of atoms within molecules. Resonance occurs when multiple Lewis structures can be drawn for a molecule, with the true structure being a hybrid of these structures. Isomerism refers to the existence of different compounds with the same molecular formula but different connectivity or spatial arrangement of atoms.
Sigma and pi bonds: Sigma and pi bonds are types of covalent bonds. Sigma bonds are formed by the head-on overlap of atomic orbitals, resulting in a cylindrical electron density distribution. Pi bonds are formed by the side-by-side overlap of parallel p orbitals, resulting in a bond with electron density above and below the bonding axis.