Bonding

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Created by
Megan

Cards (13)

  • An ionic bond is the electrostatic force of attraction between oppositely charged ions formed by electron transfer
  • Metal atoms lose electrons to form positive ions and non metal atoms gain electrons to form negative ions in ionic bonding
  • Ionic bonding Is stronger and the melting points higher when the ions are smaller and/or have higher charges. E.g MgO has a higher melting point than NaCl as the ions involved (Mg²+ and O²- are smaller and have higher charges than those in NaCl Na+ and Cl-)
  • In electron transfer for example Mg goes from 1s²,2s²,2p⁶,3s² to Mg²+ 1s² 2s²,2p⁶ and O goes from 1s²,2s²,2p⁴ to O²- 1s²,2s²,2p⁶
  • A covalent bond is a shared pair of electrons
  • A dative covalent bond forms when the shared paired of electrons in the covalent bond come from only one of the bonding atoms.
  • A dative covalent bond is also called a co-ordinate bond
  • Common examples you should be able to draw that contain dative covalent bond are NH4+, H3O+, NH3BF3
  • The dative covalent bond acts like an ordinary covalent bond when thinking about shaoe so in NH4+ the shape is tetrahedral
  • The direction of the arrow goes from the atom that is providing the lobe pair to the atom that is deficient
  • A metallic bond is the electrostatic force of attraction between the positive metal ions and the delocalised electrons
  • The three main factors that affect the strength of a metallic bond are
    1. Number of protons / strength of nuclear attraction (the more protons the stronger the bond)
    2. Number of delocalised electrons per atom (the outer shell electrons are delocalised) - the mire delocalised electrons the stronger the bond
    3. Size of ion - the smaller the ion, the stronger the bond
  • Mg has stronger metallic bonding than Na and hence a higher melting point. The metallic bonding gets stronger because in Mg there are more electrons in the outer shell that are released to the sea of electrons. The Mg ions is also smaller and has one more proton. There is therefore a stronger electrostatic attraction between the positive metal ions and the delocalised electrons and higher energy is needed to break bonds