1. Elements and the Periodic Table

2. Periodic table
The periodic table contains information on all the ELEMENTS in the world.
An element is a PURE substance made of atoms.
An atom is the SMALLEST thing in the world that an element can be broken down into.

3. Elements
Pure substances that cannot be separated into different substances by ordinary processes
Are the building blocks of matter
118 elements known today
Examples: carbon
gold
calcium

4. Symbols of Elements Use 1 or 2 letter abbreviations
Capitalize the first letter only
Examples:
C carbon Co cobalt
N nitrogen Ca calcium
F fluorine Br bromine
O oxygen Mg magnesium
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5. Symbols from Latin Names
Element Symbol Latin name
Copper Cu cuprum
Gold Au aurum
Lead Pb plumbum
Mercury Hg hydrargyrum
Potassium K kalium
Silver Ag argentum
Sodium Na natrium
Tin Sn stannum
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6. Learning Check Select the correct symbol for each: A. Calcium
1) C 2) Ca 3) CA
B. Sulfur
1) S 2) Sl 3) Su
C. Iron
1) Ir 2) FE 3) Fe
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7. Solution Select the correct symbol for each: A. Calcium 2) Ca
B. Sulfur
1) S
C. Iron
3) Fe
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8. Learning Check Select the correct name for each: A. N
1) neon 2) nitrogen 3) nickel
B. P
1) potassium 2) phogiston 3) phosphorus
C. Ag
1) silver 2) agean 3) gold
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9. Solution Select the correct name for each: A. N 2) nitrogen B. P
3) phosphorus
C. Ag
1) silver
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10. The periodic table arranges the elements according to similarities in their chemical and physical properties.

11. Physical properties
The characteristics of a substance that can be observed without changing the substance.
Colour
Size
Lustre
Shape
Density
Freezing and Boiling Points
Smell

12. Chemical properties Number of valence electrons Reactivity
Type of reactions typically made
Response to water/ acid…

13. The Periodic table is organised into GROUPS and PERIODS

14. Groups
The vertical columns are called groups (sometimes called families)
Each group of elements has similar PHYSICAL AND CHEMICAL properties

15. Groups in the Periodic Table

16. The periodic table and electrons
The location of an element on the periodic table is directly related to the number and arrangement of the electrons of that element

17. Valence Electrons
The number of valence electrons in an atom may also be indicated.
Valence electrons are the electrons in the outer energy level of an atom.
These are the electrons that are transferred or shared when atoms bond together.

18. Reminders:
Valence electrons – electrons in the outer energy level of an atom
Mass number – number of protons plus neutrons in the nucleus of a particular kind of atom
Atomic number – the number of protons in a particular kind of atom

19. Periods on the Periodic Table
Horizontal rows from Group 1 to Group 8.
Numbered 1, 2, 3, ….
Include representative elements and transition elements

20. Periods on the Periodic Table1 2 3 4 5 6

21. Periods

22. Groups versus periods Groups Periods Columns of elements
Elements in each group have similar but not identical properties.
For example,Group 1A: [ lithium (Li), sodium (Na), potassium (K), and other members of family IA] are all soft, white, shiny metals.
All elements in a group have the same number of valence electrons.
Horizontal row of elements
The elements in a period do NOT have similar chemical or physical properties.
Elements in same period have same number of energy levels (electrons)
Properties change greatly across every period
The first element in a period is always an extremely active solid. The last element in a period is always an inactive gas.

23. Periodic Trends Atomic mass increases as you move right and down
Elements of a period are listed consecutively in order of increasing atomic number 3 4 5 6 7 8 9 10

26. Spotting characteristics 1: Metals versus non-metals

27. Metals

28. Properties of Metals Physical properties
Metals are good conductors of heat and electricity.
Metals are shiny.
Metals are ductile (can be stretched into thin wires).
Metals are malleable (can be pounded into thin sheets)
Usually solid at room temperature (except mercury)
A chemical property of metal is its reaction with water which results in corrosion.

29. Non-Metals

30. Non-Metals
Located on the right side of the periodic table (except for Hydrogen)
Usually found as a gas at room temperature
Not malleable or ductile
Do not conduct heat or electricity well
The noble gases are the only group that contains ALL non-metals
Sulphur

32. Metals versus non-metals

33. Metals and Nonmetals NONMETALS METALS METALS Transition metals
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34. Physical Properties of NONMETALS
Nonmetals are insulators.
They do not conduct electricity or heat well.
The atoms in non-metals do not have ‘loose’ electrons.
When electricity or heat touches a non-metal, the energy does not move quickly through the material.
What would you rather stir a hot pot with—a wooden spoon or a metal spoon?

35. Physical Properties of NONMETALS
Nonmetals are soft and brittle (except for diamonds and graphite.
Sulphur

36. An interesting element: Carbon
Ever break the point of your pencil? That’s because it’s made of graphite, a substance made up completely of Carbon—a brittle nonmetal.
Carbon atoms in graphite
However diamonds, the hardest material of all, are made of the same element: Carbon. Look at how the carbon atoms are arranged in diamonds—why do you think diamonds are harder than graphite?
You may also want to discuss how we are using carbon to create new materials such as nanotubes, or discuss buckeyballs.

37. Metalloids

38. The elements contained in the classification of Metalloids:

39. Metalloids (also called semi-metals)
Can have both metallic and non-metallic properties
Usually ductile and malleable
Some metalloids conduct electricity better than non-metals but worse than metals – these are termed semiconductors

40. METALLOIDS
Elements classified as Metalloids have physical properties of both metals and non-metals.
Some are shiny, some are dull, they are somewhat malleable and ductile, and can conduct heat and electricity at a lesser level than metals.
SILICON
ARSENIC
BORON

41. METALLOIDS
Some metalloids are useful semiconductors, which are used in electronics (radio, computers, telephones, etc.)
They are useful because they conduct just the right amount of electricity or heat.

42. More about metals The alkali metals The alkaline earth metals
Do all metals behave the same?

43. Where do we find METALS?
Some metals like gold, silver, and platinum are found as pure substances in the earth’s crust because they are least reactive.
Most metals are reactive and are found as oxides (react with oxygen), carbonates (react with carbon), sulfides (react with sulfur).
Minerals : are elements or compounds which occur naturally inside the earth’s crust.
Ore : is a mineral from which metals can be extracted profitably.

45. Metals are not all equally reactive

46. Alkali Metals H Li Na K Rb Cs Fr

47. Alkali Metals Elements found in Group 1A
Most reactive of all metals – SUPER-REACTIVE (so need to be stored in oil)
Not found as mono-elements in nature – they need to be extracted from compounds
Each alkali metal has one valence electron (which is EASY to lose…)

48. Testing reactivity… Drop it in water Heat it Drop it in acid
Mix it with oxygen
Displacement reactions…

49. Alkaline Earth Metals Be Mg Ca Sr Ba Ra

50. Alkaline Earth Metals Elements found in Group 2A
Combine readily with other elements
Have low electron affinities and electronegativities
The radius is of the nucleus is smaller than that of group I metals
Each alkaline earth metal has 2 valence electrons

51. Transition Metals

52. Transition elements
Elements found in the middle block of the periodic table
The elements occur often in nature as uncombined elements
Similar properties, but not similar number of valence electrons.
Iron is the most commonly used transition element and is the second most common element in the earth’s crust

53. Halogens F Cl Br I At

54. Halogens Elements found in Group 7A Very reactive elements
Each halogen has 7 valence electrons

55. Noble Gases He Ne Ar Kr Xe Rn

56. Noble Gases Elements found in Group 8A
Very stable because their outer energy level is full
Each noble gas has 8 valence electrons

57. Lanthanide and Actinide Series
Lanthanide Series
Actinide Series

58. Bohr model relates to periodic table
The first period on the table has two elements…and the first energy level holds two electrons.
The second period has eight elements…and the second energy level holds eight electrons.

59. Bohr’s atomic model relates to periodic table
The first period on the table has two elements…and the first energy level holds two electrons.
The second period has eight elements…and the second energy level holds eight electrons.
Period determines the number of energy levels.
Group determines the number of electrons in the valence shell.

60. Bohr model of Carbon C p +
= 6 n
= 6
12-6

61. group 4 = 4 valence electrons
Bohr Model of Carbon e -
period 2 = 2 energy levels
group 4 = 4 valence electrons e - p +
= 6 e - e - n
= 6 e - e -