CHEM101 Lecture Notes - Lecture 6: Lattice Energy, Ionization Energy, Electron Affinity
Document Summary
Bonds between different molecules of the same or different type. Broken when a chemical compounds undergo a phase change. Force of attraction between positive and negative ions. Occurs between atoms with low ionisation energies and atoms with ihg electron affinity. Structure is repeated many times to give crystal lattice. Basic building cell is called a unit cell. Overall energy change associated with formation of kcl is exothermic owing to the large negative lattice energy. Which is the potential energy decrease that occurs when gaseous ions that are brought together in the crystalline state. Magnitude of charges on cation and anion. Compatibility between cations and anions in the lattice structure with the packing. When high amounts of energy are needed to form ions when the atoms are involved. Allows elements that cannot readily form ionic bonds to complete an octet of electrons (eight in shell) If central atom does not have octet, form double or triple bonds.
