Definition: An Ionic bond is the electrostatic force of attraction between oppositely charged ions formed by electron transfer. 1.3 Bonding Metal atoms lose electrons to form +ve ions. Non-metal atoms gain electrons to form -ve ions. Mg goes from 1s2 2s2 2p63s2 to Mg2+ 1s2 2s2 2p6 O goes from 1s2 2s2 2p4 to O2- 1s2 2s2 2p6 Definition: covalent bond A covalent bond is a shared pair of electrons
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+ & O2- are smaller and have higher charges than those in NaCl , Na+ & Cl-
3.1.3.1 Ionic bonding
Ionic bonding involves electrostatic attraction between oppositely charged ions in a lattice. The formulas of compound ions eg sulfate, hydroxide, nitrate, carbonate and ammonium.
Students should be able to:
• predict the charge on a simple ion using the position of the element in the Periodic Table
• construct formulas for ionic compounds.
3.1.3.2 Nature of covalent and dative covalent bonds
A single covalent bond contains a shared pair of electrons. Multiple bonds contain multiple pairs of electrons.
Students should be able to represent:
• a covalent bond using a line