1. THE MODERN PERIODIC TABLE

2. Mendeleev
                   
1869 – Dmitri Mendeleev published the first periodic table

3. 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

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

5. 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

6. 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

7. 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

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

9. Henry Moseley 1887 - 1915 Studied atomic structure
As a result, the periodic table was rearranged in order of atomic number
Killed in action at Gallipolli (WWI) in 1915 at age 28; a great loss for science

10. Modern Periodic Table

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

12. Modern Periodic Table
An element’s properties can be predicted from its location in the periodic table
The elements in each group have the same number of valence electrons

13. METALS Most elements are metals
88 elements to the left of the “staircase” are metals or metal like elements

15. 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

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

17. METALS

18. Chemical Properties of Metals
Metals show a wide range of chemical properties
Reactivity – ease and speed with which an element combines, or reacts with other elements and compounds

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

20. Chemical Properties of Metals
Easily lose electrons
Corrode easily. Corrosion is a gradual wearing away
Examples of corrosion: silver tarnishing and iron rusting

21. Chemical Properties of Metals
Metal atoms give up outer electrons easily
When many atoms are combined, they “share” electrons
Metal atoms slide past each other, held together but not locked in place
Result?
Malleable, ductile, conduct electricity

22. Families of Metals

23. Group 1 – Alkali Metals

24. Group 1 – Alkali Metals One valence electron Li Most reactive Soft
Low densities
Low melting point Li Na

25. Group 1 – Alkali Metals
Combine with negative ions to form salts

26. Group 1 – Alkali Metals Na, K
Na compounds in large amounts in sea water
Na and K both essential for life

27. Group 1 – Alkali Metals

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

29. Group 2 – Alkaline Earth Metals
Magnesium and calcium are common alkaline earth metals
Calcium compounds make up much of your bones and teeth

30. Group 2 – Alkaline Earth Metals
Magnesium, when combined with aluminum, makes a strong but lightweight alloy

31. Group 2 – Alkaline Earth Metals

32. Transition Metals

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

34. Transition Metals Transition metals are fairly stable
React slowly or not at all

35. Rare Earth Metals Lanthanides and Actinides
Lanthanides are soft, shiny metals with high conductivity
Actinides are all radioactive. Some not found in nature

36. NONMETALS Nonmetals are found to the right of the stair step line
17 elements
Make up most of the human body

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

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

39. Physical Properties of 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.

40. Chemical Properties on Nonmetals
Have many electrons in their highest energy level
Form negative ions
Gain electrons
Noble gases do not react with other elements

41. Chemical Properties of Nonmetals
Tend to gain electrons
React with metals to form salts
React with other nonmetals and share electrons

42. Chemical Properties of Nonmetals
Diatomic molecule – when nonmetals form molecules of two identical atoms
H H

43. METALLOIDS
Elements that border the zigzag line have properties of both metals and nonmetals
These elements are called metalloids.

44. Physical Properties of Metalloids
Solids
Can be shiny or dull
Ductile
Malleable
Conduct heat and electricity better than nonmetals, but not as well as metals

45. Physical Properties of Metalloids
Some are semiconductors, such as Si (silicon)

46. Ionic Compounds
Since metals tend to lose electrons and nonmetals tend to gain electrons, metals and nonmetals like to form compounds with each other
These compounds are called ionic compounds

47. Boron Group Boron is the only element in group 13 that is not a metal
B is brittle, black metalloid
Al is the most abundant metal in the earth’s crust
Aluminum has many uses

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

49. Group 14 – Carbon Group Carbon is the element essential for life
It is unique because it can link up with other C atoms to form long chains
                          

50. Carbon Group
Si and Ge are metalloids
Sn and Pb are metals

51. Group 15 – Nitrogen Group N and P are nonmetals N makes up 80% of air
N is essential to life
N-fixing bacteria take N from air and change into compounds plants can use

52. Group 15 – Nitrogen Group P (Phosphorus) also necessary for life
P in bones, teeth and DNA
As and Sb are metalloids

53. Group 16 – Oxygen Group O is the most abundant element on earth
O is very reactive and can combine with almost every other element
S, Se are also nonmetals

54. Group 17 -- Halogens Halogen means “salt-former”
Halogens combine with metals to form salts
Have 7 valence electrons
F is the most reactive nonmetal

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

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

58. Hydrogen H does not fit in with any group
Reacts easily with other elements
Can act like a metal or a nonmetal

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

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

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

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