Bonding

• Ionic bonding occurs when one atom transfers electrons to another atom, resulting in the formation of ions.
• When a metal and a non-metal react together

  Metal atom loses electrons and becomes a cation (+), non-metal gains electrons and becomes an anion (-)
• Ionic bonding


  Strong electrostatic forces of attraction between oppositely charged ions
• When non-metals bond together

  Each atom gives one electron to form a bond pair in which the electron spins are opposed
• Covalent bond


  Electrostatic attraction between the positive nuclei of the bonded atoms and the shared electrons between them
• Covalent bonding


  Atoms share electrons in their outermost shells
• Coordinate bonding


  Electronegativity is a measure of how strongly atoms attract electrons in a covalent bond
• Electronegativity


  Measure of how strongly atoms attract electrons in a covalent bond
• Polar bonds


  Substances contain bonds that are intermediate in character between pure covalent and pure ionic bonds
• Degree of ionic or covalent character


  Depends on the difference in electronegativity between the bonded atoms
• Forces between molecules


  • Dipole-dipole forces
  • Induced dipole-induced dipole forces
  • Hydrogen bonds
• Polar molecules


  Have dipoles, one end has a slightly positive charge, the other a slightly negative charge due to a difference in electronegativities between the atoms in the molecule
• Attraction between molecules


  If dipoles arrange themselves so that the negative region of one molecule is close to the positive region of another molecule
• Dipoles arrange themselves


  If the negative region of one molecule is close to the positive region of another molecule, there will be an attraction between them
• Even molecules with no dipoles show intermolecular bonding
• Temporary dipole


  Occurs when the distribution of the electron cloud around the nuclei is not symmetrical at a particular moment
• Formation of temporary dipole


  The δ+ end of the molecule can pull the electron cloud of a neighbouring molecule towards it, inducing a temporary dipole in the neighbouring molecule. The two dipoles are attracted to each other
• Induced dipole-induced dipole forces

  The second dipole induces a dipole in a third molecule, and so on, aligning the dipoles correctly to produce an attraction between the molecules
• Strength of induced dipole-induced dipole forces

  Increases with increasing numbers of electrons in the molecule, leading to stronger forces between the molecules. These forces, along with temporary dipoles, are called van der Waals forces
• Elements for special intermolecular forces

  • Hydrogen atoms bonded to fluorine, oxygen, or nitrogen
• Hydrogen bonding


  Increases boiling points and solubility due to the stronger hydrogen bonds compared to van der Waals forces
• Metals tend to lose electrons to form positive ions (cations), while nonmetals tend to gain electrons to form negative ions (anions).
• Covalent bonds are formed between nonmetal atoms by sharing pairs of electrons.
• Metallic bonding occurs between metal atoms, where delocalized electrons move freely throughout the lattice structure.
• Ionic bonding is the transfer of electrons from one atom to another.
• Intermolecular forces

  occurs between molecules
• Intramolecular forces

  Occurs within molecules
• Electronegativity

  The measure of the electron attracting power of an atom in a covalent bond