CHAPTER 10: Chemical  Periodicity

• Periodicity in Physical Properties
• Periodicity in Chemical Properties
• Period 3 Oxides
• Period 3 Chlorides

Learning outcomes:

• describe qualitatively (and indicate the periodicity in) the variations in atomic radius, ionic radius, melting point and electrical conductivity of the elements (see the Data Booklet).
• explain qualitatively the variation in atomic radius and ionic radius
• interpret the variation in melting point and in electrical conductivity in terms of the presence of simple molecular, giant molecular or metallic bonding in the elements
• explain the variation in first ionisation energy
• describe the reactions, if any, of the elements with oxygen (to give Na2O, MgO, Al2O3, P4O10, SO2, SO3), chlorine (to give NaCl , MgCl2, Al2Cl6, SiCl4, PCl5) and water (Na and Mg only).
• state and explain the variation in oxidation number of the oxides and chlorides in terms of their valence shell electrons
• describe the reactions of the oxides with [treatment of peroxides and superoxides is not required]
• describe and explain the acid/base behaviour of oxides and hydroxides including, where relevant, amphoteric behaviour in reaction with sodium hydroxide (only) and acids
• describe and explain the reactions of the chlorides with water
• interpret the variations and trends in (f), (g), (h), and (i) in terms of bonding and electronegativity.
• suggest the types of chemical bonding present in chlorides and oxides from observations of their chemical and physical properties
• predict the characteristic properties of an element in a given group by using knowledge of chemical periodicity 
• deduce the nature, possible position in the Periodic Table, and identity of unknown elements from given information about physical and chemical properties