[note][tr] Diversity 1.1 Ionic Bonding 2024 [modofied for 2025 9 july 2024]

1 D 1.2 Ionic Bonding CHIJ ST. NICHOLAS GIRLS’ SCHOOL Sec 2 Science 2024[modified for 2025 9 july 2024] Diversity 1 : Exploring Diversity of Matter by their Physical properties D 1.1 Ionic Bonding Students should be able to : (a) Describe the formation of ionic bonds between metals and non-metals eg in NaCl and MgCl2, using ‘dot and cross’ diagrams to illustrate (b) State that ionic materials contain a giant lattice in which the ions are held by electrostatic attraction, e.g. NaCl (diagrams of ionic lattices will not be required) (c) Deduce the formulae of other ionic compounds from diagrams of their lattice structures, limited to binary compounds (d) Relate the physical properties (including electrical property of ionic compounds to their lattice structure) (e) Explain how to derive the chemical formula from the charges of the ions present Students should be able to : (a) explain the choice of the main classes of materials (metals, ceramics, glass, plastics, fibres) in the production of common household items, in terms of their properties, e.g. density ,strength, hardness, flexibility, electrical conductivity, thermal conductivity, boiling/melting point (b) use data on the properties of different materials to evaluate their uses (c) relate the properties of substances to type of bonding and structure :

2 D 1.2 Ionic Bonding Ionic Bond What are ions? : http://youtu.be/900dXBWgx3Y 1. Ions are formed when atoms loses outer/valence shell electrons or gain electrons into the outer/valence shell. 2. The charge on the ion is either positive or negative. 3. If an atom loses electrons, the ion formed is positively charged because the number of protons present is more than the number of electrons left. 4. If an atom gains electrons, the ion formed is negatively charged because the number of electron is more than the number of protons. Ionic compound An ionic compound is formed when a metal reacts with a non-metal. The metal atom loses electrons to the non-metal aroms. This results in forming positive metal ions and negative non-metal ions. These oppositely charged ions are attracted together to form ionic compound. http://youtu.be/zpaHPXVR8WU Using the reaction between sodium and chlorine as an example:  Cations and anions are attracted to one another through strong electrostatic forces of attraction. This constitutes an ionic bond.  The compound formed is called sodium chloride. Definition of ionic bond An ionic bond is the strong electrostatic forces of attraction between oppositely charged ions.  Metallic atoms lose their valence electrons to non-metallic atoms.  Metallic atoms become positive ions (cations).  Non-metallic atoms become negative ions (anions).

3 D 1.2 Ionic Bonding More practice Draw the ‘dot and cross’ diagrams to show the electronic structures of ionic compounds formed by the following elemen