Main-Group Metals

The Activity of Metals Lithium, sodium, and potassium all react with water The rate of this reaction increases as we go down this column

Class I Metals: The Active Metals Li, Na, K, Rb, Cs (Group IA) Ca, Sr, Ba (Group IIA) Class II Metals: The Less Active Metals Mg, Al, Zn, Mn Class III Metals: The Structural Metals Cr, Fe, Sn, Pb, Cu Class IV Metals: The Coinage Metals Ag, Au, Pt, Hg

The most active metals are so reactive that they readily combine with the O 2 and H 2 O vapor in the atmosphere and are therefore stored under an inert liquid, such as mineral oil.

Group IA: The Alkali Metals SymbolNameElectrons configuration 1H Hydrogen 1 3 Li Lithium2, 1 11 Na Sodium2, 8, 1 19 K Potassium2, 8, 8, 1 37 RbRubidium2, 8, 18, 8, 1 55 CsCesium , 8, 1 87 FrFrancium , 8, 1

Important trends down the group with increase in atomic number: 1. The atoms get bigger (as more electron shells are added). 2. The element gets more reactive. 3. Down the group the reaction gets faster and more violent. 4. Generally the hardness decreases (can be cut with a knife). 5. The melting point and boiling point generally decrease. 6. Generally the density increases. (due to increase in atomic mass) 7. Rubidium and cesium are very explosive with water. 8. Ionization energy decreases.

Reactions Halogens; 2 Na(s) + Cl 2 (g)→2 NaCl(s) Hydrogen: 2K(s) + H 2 (g) → 2 KH(s) Nitogen: 3Li + → Li 3 N Oxygen: 4 Li(s) + O 2 (g) → 2 Li 2 O(s) oxide 2 Na(s) + O 2 (g) → Na 2 O 2 (s) peroxides K(s) + O 2 (g) → KO 2 (s) superoxides Water: 2Na(s) + 2H 2 O (l) → 2 Na OH - + H 2

Group IIA: The Alkaline-Earth Metals SymbolNameElectrons configuration 4 Be Beryllium 2, 2 12 Mg Magnesium2, 8,2 20 Ca Calcium2,8,8,2 38 Sr Strontium2,8……….2 56 BaBarium2,8………….2 88 RaRadium2,8…………….2 M → M 2 + →+ 2e -

Reactions Halogens; Mg (s) + Cl 2 (g)→MgCl 2 (s) Hydrogen: Ca(s) + H 2 (g) → CaH 2 (s) Nitogen: 3 Mg(s) + N 2 (g) → Mg 3 N 2 (s) Oxygen: 2 Mg(s) + O 2 (g) → 2 MgO(s) oxide Ba(s) + O 2 (g) → BaO 2 (s) peroxides Ca,Sr, Ba Water: Ca(s) + 2 H 2 O (l) →Ca 2+ (aq) + 2 OH - (aq) + H 2 (g) Ca,Sr, Ba Steam Mg(s) + H 2 O (g) → MgO(s) + H 2 (g)

Group IIIA SymbolName Electrons configuration 5B5B Boron 2, 3 13 Al Aluminum 2, 8, 3 31 Ga Gallium 2, 8,18, 3 49 In Indium 2, 8, 18, 18, 3 81 TlThallium 2, 8, 18, 32, 18, 3

Reactions 2 Al(s) + 3 Br 2 (l)→ Al 2 Br 6 (s) 4 Al(s) + 3 O 2 (g) → 2 Al 2 O 3 (s) 16 Al(s) + 3 S 8 (s) → 8 Al 2 S 3 (s) Aluminum reacts with concentrated acids 2 Al(s) + 6 H + (aq) → 2 Al 3+ (aq) + 3 H 2 (g) Aluminum reacts with concentrated bases 2 Al(s) + 2 OH - (aq) + 6 H 2 O(l) → 2 Al(OH) 4 - (aq) + 3 H 2 (g)

Group IVA: Tin and Lead SymbolName Electrons configuration 6C6C Carbon 2, 4 14 Si Silicon 2, 8, 4 32 Ge Germanium 2, 8,18, 4 50 Sn Tin 2, 8, 18, 18, 4 82 PbLead 2, 8, 18, 32, 18, 4 12Dr.Riham Hazzaa

Lead reacts with air to form a thin coating of PbO and/or PbCO 3 2 Pb(s) + O 2 (g) → 2 PbO(s) PbO(s) + CO 2 (g) → PbCO 3 (s) Tin does not react with either air or water at room temperature Reacts with hot air Sn(s) + O 2 (g) → SnO 2 (s) Reacts with steam Sn(s) + 2 H 2 O(g) → SnO 2 (s) + 2 H 2 (g) 13Dr.Riham Hazzaa

Tin, when heated, reacts with either concentrated hydrochloric acid or concentrated sulfuric acid. Sn(s) + 2 H + (aq)→ Sn 2+ (aq) + H 2 (g) Lead reacts slowly with hydrochloric acid at room temperature and with concentrated sulfuric acid at temperatures above 200C. Pb(s) + 2 H + (aq) → Pb 2+ (aq) + H 2 (g) 14Dr.Riham Hazzaa