THE MODERN PERIODIC TABLE

1. THE MODERN PERIODIC TABLE

2. Modern Periodic Table

3. Mendeleev • 1834 - 1907 • 1869 – Dmitri Mendeleev published the first periodic table

4. Mendeleev • Born in Siberia, the last of 14-17 children • Father blind, mother ran glass factory • When he finished high school, his father died and the factory burnt down

5. Mendeleev • His mother took him to St. Petersburg to study science • Denied admission to the university, he studied at a school for teachers

6. Mendeleev • In time, he became a professor of chemistry at the U. of St. Petersburg • While writing a chemistry textbook, he developed the periodic table

7. Mendeleev • Where a gap existed in his table, he predicted a new element would be found and deduced its properties • He was right. Three elements were found during his lifetime • Ga, Sc, Ge

8. Mendeleev • The discovered elements provided the strongest support for his periodic table • It is a cornerstone in chemistry and in our understanding of how the universe is put together

9. Mendeleev • Mendeleev’s table arranged the elements in order of increasing atomic mass

10. Modern Periodic Table • Square of the periodic table contains an element’s atomic #, chemical symbol, atomic mass

11. Modern Periodic Table • The elements in each group have the same number of valence electrons

12. METALS • Most elements are metals • 88 elements in total

13. Physical Properties of Metals • Luster (shininess) • Good conductors of heat and electricity • High density (heavy for their size) • High melting point • Some metals (Fe, Co and Ni) are magnetic

14. Physical Properties of Metals • Ductile (most metals can be drawn out into thin wires) • Malleable (most metals can be hammered into thin sheets)

15. Chemical Properties of Metals • Metals show a wide range of chemical properties • Reactivity – ease and speed with which an element combines or reacts • Group 1 and 17 VERY reactive

16. Chemical Properties of Metals • Some metals are very reactive, some do not react easily • Alloy – mixture of metals • Examples: bronze, brass, stainless steel

17. Chemical Properties of Metals • Easily lose electrons (Group 1 and 2) • Corrode easily. Corrosion is a gradual wearing away • Examples of corrosion: silver tarnishing and iron rusting

18. Families of Metals

19. Group 1 – Alkali Metals

20. Group 1 – Alkali Metals • One valence electron • Most reactive of all metals • Soft • Low densities • Low melting point

21. Group 1 – Alkali Metals • Na, K • Na compounds in found in sea water • Na and K both essential for life

22. Group 1 – Alkali Metals

23. Group 2 – Alkaline Earth Metals • Two valence electrons • Group 2 • Very reactive

24. Group 2 – AlkalineEarth Metals • Magnesium and calcium are common alkaline earth metals • Calcium compounds make up much of your bones and teeth

25. Group 2 – Alkaline Earth Metals

26. Transition Metals

27. Transition Metals • Elements in Groups 3 – 12 • Bridge between very reactive metals on left side and less reactive metals on the right side

28. Rare Earth Metals • Two rows on the bottom of the table • Lanthanides and Actinides • Lanthanides are soft, shiny metals with high conductivity • Actinides are all radioactive.

29. NONMETALS • Nonmetals are found to the right of the stair step line - 17 elements in total • Make up most of the human body (oxygen, carbon, nitrogen and hydrogen)

30. Physical Properties of Nonmetals • The physical properties of nonmetals are opposite to those of metals

31. Physical Propertiesof Nonmetals • No luster (dull appearance) • Poor conductor of heat and electricity • Brittle (breaks easily) • Not ductile • Many are gases at room temperature

32. Physical Propertiesof Nonmetals • Not malleable • Low density • Low melting point • Elements in this group have one valence electron • How does this affect their reactivity? • It makes them VERY REACTIVE.

33. Chemical Properties on Nonmetals • Have many electrons in their highest energy level (shell) • Form negative ions • Gain electrons • Noble gases do not react with other elements (OUTER SHELL IS FULL)

34. Chemical Propertiesof Nonmetals Diatomic molecule – when nonmetals form molecules of two identical atoms H H

35. METALLOIDS • Elements that border the zigzag line • Have properties of both metals and nonmetals • 7 in total • Silicon, Boron, Antimony, Arsenic, Tellurium

36. Physical Propertiesof Metalloids • Solids • Can be shiny or dull • Conduct heat and electricity better than nonmetals, but not as well as metals

37. Chemical Propertiesof Metalloids • Tend to gain and lose electrons • React with metals to form salts • Some act like metals, some act like nonmetals

38. Carbon Group • Carbon is the only nonmetal in Group 14 • Two common forms – graphite and diamond • Each element has four valence electrons

39. Group 15 – Nitrogen Group • N and P are nonmetals • N makes up 80% of air • N is essential to life

40. Group 17 -- Halogens • Halogens combine with metals to form salts • Have 7 valence electrons • MOST REACTIVE of NON-metals

42. Group 18 – The Noble Gases • Colorless gases • Do not bond or combine with other elements • Outer electron shell is full

43. Group 18 – The Noble Gases • He is the second lightest gas

44. Hydrogen • H does not fit in with any group (yet can be in either GROUP 1 or GROUP 17) • Reacts easily with other elements

45. QUIZ YOURSELF! • What are the rows across the periodic table called? • Answer: PERIODS

46. QUIZ YOURSELF! • What is the term for the vertical columns in the Periodic Table? • Answer: Groups or Families

47. QUIZ YOURSELF! • How are the elements arranged in the periodic table? • In order of increasing atomic number

48. QUIZ YOURSELF! • What is the most reactive group of metals? ALKALI METALS -- GROUP 1