1. Topic 3.1 The periodic table 1

2. Assessment Statements 3.3.1 Discuss the similarities and differences in the chemical properties of elements in the same group. 3.3.2 Discuss the changes in nature, from ionic to covalent and from basic to acidic, of the oxides across period 3. 2

3. Group 1A Elements (ns 1, n  2) 8.6

4. Discuss the similarities and differences in the chemical properties of elements in the same group. Alkali Metals Reaction with water 2M (s) + 2H 2 O (l)  2M + (aq) + 2OH - (aq) + H 2 (g) where M represents Li,Na,K,Rb, or Cs 2Na (s) + 2H 2 O (l)  2Na + (aq) + 2OH - (aq) + H 2 (g) Reactivity increases down the group 4

5. Discuss the similarities and differences in the chemical properties of elements in the same group. Alkali Metals Reaction with halogens 2M (s) + X 2 (g)  2MX (s) where M represents Li,Na,K,Rb, or Cs Where X represents F,Cl,Br, or I 2Na (s) + Cl 2 (g)  2NaCl (s) Reactivity increases down the group 5

6. The Standard Electrode potential is a measure of reducing agent strength, more negative values have a greater tendency to lose an electron in aqueous solution. 6

7. Group 7A Elements (ns 2 np 5, n  2) 8.6

8. Discuss the similarities and differences in the chemical properties of elements in the same group. Halogens Reaction with halide ions Cl 2 reacts with Br - and I - Cl 2 (aq) + 2Br - (aq)  2Cl - (aq) + Br 2 (l) Cl 2 (aq) + 2I - (aq)  2Cl - (aq) + I 2 (s) Br 2 reacts with I- Br 2 (aq) + 2I - (aq)  2Br - (aq) + I 2 (s) I 2 non-reactive with halide ions 8

9. Displacement reactions To put it simply, a MORE reactive halogen will displace a LESS reactive halogen from a solution of its salt. F Cl Br I Decreasing reactivity Potassium chloride KCl (aq) Potassium bromide KBr (aq) Potassium iodide KI (aq) Chlorine Cl 2 2KCl + Br 2 2KCl + I 2 Bromine Br 2 No reaction 2KBr + I 2 Iodine I 2 No reaction Example: 2KBr + Cl 2  2KCl + Br 2

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11. Discuss the changes in nature, from ionic to covalent and from basic to acidic, of the oxides across period 3. Metallic Oxides in Period 3 Sodium oxide: Na 2 Oionic Magnesium oxide: MgOionic Aluminum oxide: Al 2 O 3 ionic Metalloid oxide in Period 3 Silicon dioxide: SiO 2 covalent Nonmetallic oxides in Period 3 Tetraphosphorus decoxide: P 4 O 10 covalent Sulfur trioxide: SO 3 covalent Dichlorine heptoxide: Cl 2 O 7 covalent 11

12. Discuss the changes in nature, from ionic to covalent and from basic to acidic, of the oxides across period 3. Acidic/Basic Metallic oxides in Period 3 are basic Sodium oxide: Na 2 O + H 2 O  2 NaOH basic Magnesium oxide: MgO + H 2 O  Mg(OH) 2 basic Aluminum oxide: Al 2 O 3 + H 2 O  2 Al(OH) 3 amphoteric Metalloid oxide in Period 3 is acidic Silicon dioxide:SiO 2 + H 2 O  H 2 SiO 3 acidic Nonmetallic oxides in Period 3 are acidic Tetraphosphorus decoxide: P 4 O 10 + 6H 2 O  4H 3 PO 4 acidic Sulfur trioxide: SO 3 + H 2 O  H 2 SO 4 acidic Dichlorine heptoxide: Cl 2 O 7 + H 2 O  2HClO 4 acidic Argon does not form an oxide 12

13. The Third Period Chlorides FormulaNaClMgCl 2 AlCl 3 Al 2 Cl 6 SiCl 4 PCl 3 (PCl 5 ) S 2 Cl 2 Cl 2 State 25 o C Solid Liquid (Solid) LiquidGas Melting Point o C 801714178 Sublimes -70-112-80-101 Boiling Point o C 14131412---5876136-35 Electrical Conductivity Good PoorNone Bonding Ionic Covalent  Reaction with Water Dissolves easily DissolvesFumesandProducesHCl Nature of water solution NeutralWeakly Acidic 13 NaCl and MgCl 2 are ionic compounds. The others are covalent NaCl is neutral when dissolved in water. MgCl 2 is weakly acidic. All other chlorides, including Al 2 Cl 6, react vigorously with water to produce hydrochloric acid and fumes of hydrogen chloride: 2 AlCl 3 (s) + 3 H 2 O (l) à Al 2 O 3 (s) + 6 HCl (aq) Chlorine with itself in water: Cl 2 (g) + H 2 O (l) à HClO (aq) + HCl (aq)

14. NaCl and MgCl 2 are ionic compounds. The others are covalent NaCl is neutral when dissolved in water. MgCl 2 is weakly acidic. All other chlorides, including Al 2 Cl 6, react vigorously with water to produce hydrochloric acid and fumes of hydrogen chloride: 2 AlCl 3 (s) + 3 H 2 O (l)  Al 2 O 3 (s) + 6 HCl (aq) Chlorine with itself in water: Cl 2 (g) + H 2 O (l)  HClO (aq) + HCl (aq) 14

15. The Third Period Oxides FormulaNa 2 OMgOAl 2 O 3 SiO 2 P 4 O 10 (P 4 O 6 ) SO 3 (SO 2 ) Cl 2 O 7 (Cl 2 O) State 25 o C Solid Liquid (Gas) Gas Melting Point o C 12752852202716102417-92 Boiling Point o C ---3600298022301754580 Electrical Conductivity Good Very poorNone Structure<-Ionic->Covalent Network Covalent Reaction with water Forms NaOH (Strong Base) Forms Mg(OH) 2 (Weak Base) No Reaction No Reaction Forms H 3 PO 4 (Acid) Forms H 2 SO 4 (Strong Acid) Forms HClO 3 (Strong Acid) Nature of the Oxide Basic AmphotericAcidic 15

16. Revision: Terms to Know Group Period Alkali metals Halogens Ionic radius Electronegativity First ionization energy 16