2. Periodic Table T. M. Yeung 2000

4. CLASSIFYING ELEMENTS zIn 1869, the Russian chemist Mendeleev arranged the elements known at that time in the Periodic Table of Elements.

8. Periodic Table zElements are arranged in order of increasing atomic number. zVertical column:-- Group. zGroup no. = no. of outermost shell electron z(Except hydrogen and helium) zHorizontal row:-- Period. zPeriod no. = no. of occupied electron shells

9. Electron arrangement of chlorine atom no. of occupied electron shells = 3 = period no. no. of electrons in the outermost shell = 7 = group no. (VII)

10. ELECTRONIC ARRANGEMENT

11. Periodic Table zGroup I elements zGroup II elements zGroup VII elements zGroup 0 elements zAlkali metals zAlkaline earth metals zHalogens zNoble gases/ Inert gases

12. The Period 3 elements. (Argon is contained in a light bulb.) sodium magnesium aluminium silicon phosphorus (red) sulphur chlorine argon

13. Change in Metallic Character across a Period Increasing Metallic Character Increasing Non-metallic Character

14. Change in Reactivity across a Period Unreactive non-metal Reactive non-metal Reactive metal Semi-metal Less reactive metal Less reactive non-metal

15. Change of the metal/non-metal character in Periods 2 and 3 of the Periodic Table.

16. Class-work a. Group VII and period 4 b. Non-metal c. Bromine, Br

17. Some Group I elements. LithiumSodiumPotassium RubidiumCaesium oil

18. Group I:-- Alkali Metals zLithiumLi2, 1 zSodiumNa2, 8, 1 zPotassiumK2, 8, 8, 1 z... zThe atoms have one outermost shell electron. zAll are soft and can be cut by knife.All are soft and can be cut by knife.

19. Reactions of some Group I elements with water. lithium sodium potassium

20. Group I:-- Alkali Metals zAll are reactive metals. They have to be stored under oil to stop them reacting with oxygen in air. Sodium + oxygen --> sodium oxide zAll react with water vigorously. Sodium + water --> sodium hydroxide + hydrogen gas

21. Trend of reactivity of Group I elements. (least reactive) (most reactive) reactivity increases down the group

22. Group II:-- Alkaline Earth Metals zBerylliumBe2, 2 zMagnesiumMg2, 8, 2 zCalciumCa2, 8, 8, 2 z... zThe atoms have two outermost shell electrons. zAll react vigorously with dilute acids.All react vigorously with dilute acids.

23. Group II:-- Alkaline Earth Metals Magnesium + hydrochloric acid --> Magnesium chloride + hydrogen gas zAll react with water slowly. Magnesium + water --> Magnesium hydroxide + hydrogen gas

24. Some Group VII elements: chlorine, bromine and iodine. chlorine iodine bromine

25. Group VII:-- Halogens zFluorineF2, 7 zChlorineCl2, 8, 7 zBromineBr2, 8, 18, 7 z… zAll are reactive non-metals. zAll are poisonous. zAll form diatomic molecules. (e.g. F 2, Cl 2 )

26. Reactivity of Group VII elements decreases down the group. (most reactive) (least reactive) reactivity decreases down the group

27. Group 0/VIII:-- Noble Gases zHeliumHe2 zNeonNe2, 8 zArgonAr2, 8, 8 zKryptonKr2, 8, 18, 8 zAll are colourless gases. zAll are very stable and do not take part in chemical reactions. They are therefore also called inert gases.

28. Uses of Argon Gas: Filling light bulb and fluorescent tube fluorescent tube light bulb

29. Some common transition metals. ironzincsilver coppergoldplatinumnickel