The Periodic Table Lecture Notes 2021 H1_tutor

St Andrew’s Junior College JC1 H1 Chemistry 2021 1 St Andrew’s Junior College H1 Chemistry 2021 Lecture Notes 6 The Periodic Table Assessment Objectives: Trends and variations in atomic and physical properties For elements in the third period (sodium to chlorine), and in Group 17 (chlorine to iodine) candidates should be able to (a) recognise variation in the electronic configurations across a Period and down a Group (b) describe and explain qualitatively the trends and variations in atomic radius, ionic radius, first ionisation energy and electronegativity: (i) across a Period in terms of shielding and nuclear charge (ii) down a Group in terms of increasing number of electronic shells and nuclear charge (c) interpret the variation in melting point and in electrical conductivity acr oss a Period in terms of structure and bonding in the elements (metallic, giant molecular or simple molecular) (d) describe and explain the trend in volatility of the Group 17 elements in terms of instantaneous dipole-induced dipole attraction Trends and variations in chemical properties For elements in the third period (sodium to chlorine) candidates should be able to (e) (i) state and explain the variation in the highest oxidation number of the elements in oxides (for Na2O; MgO; Al2O3; SiO2; P4O10; SO3) and chlorides (for NaCl; MgCl2; AlCl3; SiCl4; PCl5) (ii) state and explain the variation in bonding in oxides and chlorides in terms of electronegativity (with the exception of AlCl3) (iii) describe the reactions of the oxides with water(for Na2O; MgO; Al2O3; SiO2; P4O10; SO3) (iv) describe and explain the acid/base behaviour of oxides (for Na2O; MgO; Al2O3; SiO2; P4O10; SO3) and hydroxides (for NaOH; Mg(OH) 2; Al(OH)3), including, where relevant, am photeric behaviour in reaction with sodium hydroxide (only) and acids. (v) describe and explain the reactions of the chlorides with water (for NaCl; MgCl2; AlCl3; SiCl4; PCl5) (vi) suggest the types of structure and bonding present in the oxides and chlorides from observations of their chemical and physical properties For elements in Group 1 (lithium to caesium) and Group 17 (chlorine to iodine) candidates should be able to (f) describe and explain the relative reactivity of elements of: (i) Group 1 as reducing agents in terms of ease of loss of electron; (ii) Group 17 as oxidising agents in terms of ease of gain of electron (g) describe and explain the trend in thermal stability of Group 17 hydrides in terms of bond energies In addition, candidates should be able to: (h) predict the characteristic properties of an element in a given Group by using knowledge of chemical periodicity (i) deduce the nature, possible position in the Periodic Table, and identity of unknown elements from given information of physical and chemical properties

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