[4 marks] The sodium atom gives an electron to the chlorine atom to make the sodium and chloride ions respectively. electronic configuration of lithium =2,1 electronic configuration of chlorine=2,8,7 Lithium donates one electron to attain the noble gas(helium) configuration. This electron is then gained by the chlorine atom which becomes a negative ion. Sodium chloride is produced by reacting sodium with chlorine. sodium + chlorine sodium chloride Figure 2 shows what happens to atoms of sodium and chlorine in this reaction. Write about electron transfer in your answer. The sodium (Na) atom transfers one electron to the chlorine (Cl) atom, so that they both have full outer shells. These two ions then form sodium chloride through ionic bonding. The reaction is extremely exothermic, producing a bright yellow light and a great deal of heat energy. When sodium and chlorine atoms come together to form sodium chloride (NaCl), they transfer an electron. With filled outer shells they are no longer chemically active and can't form covalent bonds to become part of a molecule. Figure 2 Na Na + + Cl Cl 2 (a) Salt (sodium chloride) is added to many types of food. The dots (•) and crosses (×) represent electrons. Decribe, in terms of electrons ,what happens when a sodium atom reacts with a chlorine atom to form sodium chloride. Then they form ionic bonds forming sodium chloride. When they combine, sodium loses an electron, and chlorine gains the electron sodium lost. A sodium atom has 11 protons and electrons and a chlorine atom has 17 protons and electrons. The sodium atom loses an electron to become a positive ion . 0 2 . Describe what happens when a sodium atom reacts with a chlorine atom. 2 Sodium atoms react with chlorine atoms to produce sodium chloride (NaCl). Only the outer electrons are shown.

This is an example of ionic bonding. When a sodium atom transfers an electron to a chlorine atom, forming a sodium cation (Na +) and a chloride anion (Cl-), both ions have complete valence shells, and are energetically more stable.