The Periodic Table

1. The Periodic Table Properties of Elements and Trends

2. Mendeleev • The original periodic table was created by Dmitri Mendeleev. • He organized the table by atomic mass. • He predicted existence of 3 missing elements (Ga, Sc, Ge)

3. Modern Periodic Table • The modern periodic table is organized by atomic number. Henry Mosely

4. Vertical columns  called groups or families • Horizontal rows  called periods also represent the shells or energy levels • The basis of periodic law is repeating patterns.

5. Major Categories of Elements • 1) metals 2) non-metals 3) metalloids • Metals are found to the left of the “staircase” • Non-metals are found to the right of “staircase” • Metalloids are found “on” the staircase

7. Properties of Metals • Solid at room temperature (except Hg) • Shiny, Have luster • Malleable • Ductile • Generally have high melting points • Good conductor of heat and electricity • Have metallic bonds

8. Properties of Non-metals • Can be solid, liquid or gas at room temp • S  examples C, S, I2 • L  Br2 • G  O2, Ne, F2 • Allotropes- different molecular forms of the same element (different properties, too) O2 and O3 • Dull, lack luster • Brittle • Poor conductors

9. Properties of Metalloids • Solid at room temperature • Semi-conductors • Have varying properties that can be metallic or non-metallic

10. Metals tend to lose electrons to form a full valence shell and + ions. • Non-metals tend to gain electrons to form a full valence shell and – ions.

11. Groups on the Periodic Table • In general, elements found within the same group have similar chemical and physical properties. • This is mainly due to the fact that they have the same number of valence electrons.

12. Alkali Metals (Group I) • Metals • Have one valence electron • Tend to lose that one electron to become a more stable ion. • Rarely found in natural state.

13. Lithium(Li), Sodium(Na), and Potassium(K) • Three examples of alkali metals • VERY reactive metals • Exist as solids at room temperature, but are soft • Silvery-white or grayish in color

14. Lithium

15. Applications of Lithium • Compounds containing Li have many applications: • lithium hydroxide is used to absorb carbon dioxide in space vehicles • lithium is used in the manufacture of special high strength glasses and ceramics • sometimes, lithium-based compounds such as lithium carbonate (Li2CO3) are used as drugs to treat manic-depressive disorders.

16. Sodium

17. Applications of Sodium • Sodium compounds include: • "common salt" (sodium chloride, NaCl), • "soda ash" (sodium carbonate, Na2CO3) • "baking soda" (sodium bicarbonate, NaHCO3) • "caustic soda" (sodium hydroxide, NaOH), are important to the paper, glass, soap, textile, petroleum, chemical, and metal industries • sodium vapor is used in lamps for street lighting

18. Potassium

19. Applications of Potassium • The metal is the seventh most abundant and makes up about 1.5 % by weight of the earth's crust. • Potassium is an essential constituent for plant growth and it is found in most soils. • It is also a vital element in the human diet.

20. Comparing 3 Alkali Metals Lithium Potassium Sodium

27. Alkaline Earth Metals (Group II) • Metals • Have two valence electrons • Tend to lose the two electrons to become a more stable ion

28. Magnesium(Mg), Calcium(Ca) and Strontium(Sr) • Examples of alkaline earth metals • Exist as solids at room temperature • Silvery white or grayish white in color • Fairly reactive metals

29. Magnesium

30. Applications of Magnesium • Magnesium is the eighth most abundant element in the earth's crust although not found in it's elemental form. • used in flares and pyrotechnics • it is lighter than aluminum, and is used in alloys used for aircraft, car engine casings, and missile construction

31. Calcium

32. Applications of Calcium • Forms more than 3% of the earth’s crust • Is an essential constituent of leaves, bones, teeth, and shells • is a component of Portland cement

33. Strontium

34. Applications of Strontium • fireworks (red flame), flares • 90Sr is a radioactive isotope produced by nuclear fallout. 90Sr has the potential for use as lightweight nuclear producing electricity • used to produce glass for color television tubes

35. Halogens Group 17 • Have 7 valence electrons • Non-metals (F, Cl, Br, I) • F, Cl (gases), Br (liquid), I (solid) • Tend to gain one electron to form a more stable ion • Extremely reactive

36. Fluorine

37. Fluorine • Used as a toothpaste additive, in refrigerator coolants, and in Teflon

38. Chlorine

39. Chlorine • Used in water purification and bleach.

40. Noble Gases Group 18 • Very stable because of filled valence shell. • Do not react in the presence of other elements (relatively inert) • Xe can react with Fluorine (more later)

41. Argon

42. Argon • Used in light bulbs and lasers.

43. Xenon • Used in UV lamps and sun lamps in tanning salons.

44. Transition Metals • Also known as “heavy metals” • Tend to be very dense • Have varying reactivity • Have multiple oxidation states (can form more than one ion) • Have colorful ions (in solution)

45. Copper

46. Copper • Used to make the Statue of Liberty, pennies, water pipes and more.

47. Nickel

48. Nickel • Used to make coins, knives, forks and rechargeable batteries.

49. Silver

50. Silver • Used in silverware, jewelry, mirrors, and batteries.