1. The Representative Elements: Group 1A Through 4A

2. Copyright © Houghton Mifflin Company. All rights reserved. 18a–2 Figure 12.26: The electron configurations in the type of orbital occupied last for the first 18 elements

3. Copyright © Houghton Mifflin Company. All rights reserved. 18a–3 Figure 12.31: The positions of the elements considered in Example 12.8

4. Copyright © Houghton Mifflin Company. All rights reserved. 18a–4 Figure 12.35: The values of first ionization energy for the elements in the first five periods.

5. Copyright © Houghton Mifflin Company. All rights reserved. Big-Bang starts with universe a singularity with infinite density and temperature, only radiation exists sudden expansion leads to rapid drop in temperature and density nuclear particle transformations convert most of universe’s energy to protons and deuterons

6. Copyright © Houghton Mifflin Company. All rights reserved. 18a–6 Massive star in Pistol Nebula Source: NASA

7. Copyright © Houghton Mifflin Company. All rights reserved. Hydrogen Burning Hydrogen Burning (fusion) 4 1 H => 4 He + 2 positrons + 2 neutrinos + 2.5  10 6 MJ/mol after about 1/10 of hydrogen consumed, changes to helium burning

8. Copyright © Houghton Mifflin Company. All rights reserved. Helium Burning and Helium Reactions Helium Burning (fusion) 3 4 He => 12 C Helium Reactions 12 C + 4 He => 16 O 16 O + 4 He => 20 Ne 20 Ne + 4 He => 24 Mg when temperature reaches 5  10 8 K, carbon fusion

9. Copyright © Houghton Mifflin Company. All rights reserved. 18a–9 Hydrogen gas being used to blow soap bubbles Hydrogen is the lightest element. It is by far the most abundant element in the universe and makes up about about 90% of the universe by weight

10. Copyright © Houghton Mifflin Company. All rights reserved. 18a–10 Hindenberg ballooon was hydrogen rather than the safer helium

11. Copyright © Houghton Mifflin Company. All rights reserved. 18a–11 Preparation of hydrogen gas In Laboratory CaH 2 + 2H 2 O Ca(OH) 2 + 2H 2 Fe + H 2 SO 4 FeSO 4 + H 2 In Industry: Water Gas Reaction CH 4 + H 2 O (1100°C) CO + 3H 2 C(coke) + H 2 O (1000°C) CO + H 2 CO + H 2 O CO 2 + H 2

12. Copyright © Houghton Mifflin Company. All rights reserved. 18a–12 Cross-Section of Earth

13. Copyright © Houghton Mifflin Company. All rights reserved. 18a–13 Elemental Composition of Earth’s Crust

14. Copyright © Houghton Mifflin Company. All rights reserved. 18a–14 Composition of Air

15. Copyright © Houghton Mifflin Company. All rights reserved. 18a–15 Fractional Distillation of Air

16. Copyright © Houghton Mifflin Company. All rights reserved. 18a–16 Methods of Extraction of Elements

17. Copyright © Houghton Mifflin Company. All rights reserved. 18a–17 Lithium lithium stearate is mixed with oils to make all-purpose and high-temperature lubricants lithium hydroxide is used to absorb carbon dioxide in space vehicles lithium is alloyed with aluminium, copper, manganese, and cadmium to make high perfomance alloys for aircraft Bahnmetall consists of lead containing 0.04% lithium, 0.7% calcium and 0.6% sodium is harder than pure lead and was used for railroad car bearings in Germany. compounds such as LiAlH 4 and organolithium reagents (LiMe, LiPh, etc.) are very important as reagents in organic chemistry lithium is sometimes used as battery anode material (high electrochemical potential) and lithium compounds are used in dry cells and storage batteries lithium carbonate (Li 2 CO 3 ) are used as drugs to treat manic-depressive disorders.

18. Copyright © Houghton Mifflin Company. All rights reserved. 18a–18 sodium metal is used in the preparation of titanium metal from TiCl 4 the metal is used in the manufacture of sodamide, sodium cyanide, sodium peroxide, and sodium hydride the metal is used in the reduction of organic esters, and in the preparation of organic compounds the alloy with potassium, NaK, is an important heat transfer agent and a good chemical reducing agent (as some proportions of Na and K are liquid at room temperature). sodium compounds including "common salt" (sodium chloride, NaCl), "soda ash" (sodium carbonate, Na 2 CO 3 ), "baking soda" (sodium bicarbonate, NaHCO 3, "bicarb"), and "caustic soda" (sodium hydroxide, NaOH), are important to the paper, glass, soap, textile, petroleum, chemical, and metal industries sodium vapour is used in lamps for street lighting Sodium

19. Copyright © Houghton Mifflin Company. All rights reserved. 18a–19 鹼 金 屬鹼 金 屬

20. Copyright © Houghton Mifflin Company. All rights reserved. 18a–20

21. Copyright © Houghton Mifflin Company. All rights reserved. 18a–21 NIST F-1 cesium fountain clock Source: National Institute of Standards & Technology

22. Copyright © Houghton Mifflin Company. All rights reserved. 18a–22 Reserves of Select Elements

23. Copyright © Houghton Mifflin Company. All rights reserved. 18a–23 Electrolysis of Molten Magnesium Chloride

24. Copyright © Houghton Mifflin Company. All rights reserved. 18a–24 Extraction of Magnesium from Sea Water

25. Copyright © Houghton Mifflin Company. All rights reserved. 18a–25 Properties of Magnesium Atomic Number 12 Density (g/L)1.74 Melting Point ( o C) 650 Boiling Point ( o C)1090 Atomic Radius (pm) 160 Ionic Radius, Mg +2 (pm) 72 Electronegativity 1.2

26. Copyright © Houghton Mifflin Company. All rights reserved. 18a–26 Normally magnesium is coated with a layer of oxide, MgO, that protects magnesium from air and water. Magnesium metal burns with a very bright light. The picture left shows the colour arising from adding magnesium powder to a burning mixture of potassium chlorate and sucrose

27. Copyright © Houghton Mifflin Company. All rights reserved. 18a–27 Mg used in flares and pyrotechnics, including incendiary bombs. It was used in flash photography, it is used in alloys used for aircraft, car engine casings, and missile construction it is used a reducing agent for the production of uranium and other metals from their salts the hydroxide (milk of magnesia), chloride, sulphate (Epsom salts), and the citrate are used in medicine magnesium oxide is refractory and used as bricks and liners in furnaces

28. Copyright © Houghton Mifflin Company. All rights reserved. 18a–28 Boron boric acid, H 3 BO 3, is used as a mild antiseptic borax, Na 2 B 4 O 7.10H 2 O, is a cleansing flux in welding borax, Na 2 B 4 O 7.10H 2 O is a water softener in washing powders boron compounds are used in production of enamels for covering steel of refrigerators, washing machines, etc. boron compounds are extensively used in the manufacture of enamels and borosilicate glasses boron compounds show promise in treating arthritis BN is as hard as diamond. It behaves like an electrical insulator, but conducts heat like a metal. It also has lubricating properties similar to graphite

29. Copyright © Houghton Mifflin Company. All rights reserved. 18a–29 Hall-Heroult Process

30. Copyright © Houghton Mifflin Company. All rights reserved. Aluminum as Fuel Thermite Process field welding of large steel objects 2Al (s) + Fe 2 O 3(s) => Al 2 O 3(s) + Fe (l) + heat Solid Rocket Booster Engines of Space Shuttle 8Al (s) + 3NH 4 ClO 4(s) => 4Al 2 O 3(s) + 3NH 3(g) + 3HCl (g) + heat

31. Copyright © Houghton Mifflin Company. All rights reserved. 18a–31 Lead is a soft, malleable and corrosion resistant material. Lead is used to line tanks that store corrosive liquids, such as sulfuric acid (H 2 SO 4 ). Lead's high density makes it useful as a shield against X-ray and gamma-ray radiation and is used in X-ray machines and nuclear reactors. Lead is also used as a covering on some wires and cables to protect them from corrosion, as a material to absorb vibrations and sounds and in the manufacture of ammunition. Most of the lead used today is used in the production on lead-acid storage batteries, such as the batteries found in automobiles.

32. Copyright © Houghton Mifflin Company. All rights reserved. 18a–32 Roman baths such as these in Bath, England, used lead pipes for water The ancient Romans used lead to make water pipes, some of which are still in use today. Unfortunately for the ancient Romans, lead is a cumulative poison and the decline of the Roman empire has been blamed, in part, on lead in the water supply.

33. Copyright © Houghton Mifflin Company. All rights reserved. 18a–33 鉛 彈 ! 鉛 彈 ! 我打你的小蛋蛋 !

34. Copyright © Houghton Mifflin Company. All rights reserved. 18a–34 小子 你新轉來的 ?

35. Copyright © Houghton Mifflin Company. All rights reserved. 18a–35 Lead (II) oxide Galena (PbS) Minium Pb 3 O 4 (Pb +4)(Pb +2) 2 O 4