1. The Periodic Table
Chapter 6

2. Date: 1/ 6/ 2014
Bell Ringer
Explain how items in a grocery store are organized. Describe the characteristics that might be used to group produce in a store. Be specific!
In a self-service store, the products are grouped according to similar characteristics. With a logical classification system, finding and comparing products is easy. You will learn how elements are arranged in the periodic table and what that arrangement reveals about the elements.

3. Searching For an Organizing Principle
6.1
Searching For an Organizing Principle
How did chemists begin to organize the known elements?
Chemists used the properties of elements to sort them into groups.
Only 13 elements had been identified by the year Chemists knew that other elements must exist and began to use scientific methods to search for them. Ask students “What type of properties have we covered thus far?” Physical properties and Chemical properties.

4. Searching For an Organizing Principle
6.1
Searching For an Organizing Principle
Chlorine, bromine, and iodine have very similar chemical properties.
Recall: What are chemical properties?
Recall: What are physical properties?
Heat of Combustion
Reactivity with water pH
(the breaking of bonds in reactants, the forming of bonds in products)
Melting point
Freezing point
Color
Smell
Density
Chlorine, bromine, and iodine may physically look different, but have very similar chemical properties. The numbers shown are the average atomic masses for these elements. Their similarity is that they all are reactive with metals

5. People and Periodic Table
Dmitri Mendeleev
Credited with organization of FIRST periodic table
Elements were arranged by increasing atomic mass.
Elements were listed in columns so that those with similar properties were side by side.
He predicted the existence and properties of new elements (blank spaces in the first periodic table).

6. Mendeleev’s Periodic Table
6.1
Mendeleev’s Periodic Table
An Early Version of Mendeleev’s Periodic Table
In this early version of Mendeleev’s periodic table, the rows contain elements with similar properties. Observing A fourth element is grouped with chlorine (Cl), bromine (Br), and (I) iodine. What is this element’s symbol?
Note that Mendeleev developed his periodic table BEFORE scientists knew about the structure of the atom.

7. People and Periodic Table
Henry Moseley
The discovery of isotopes made it apparent that atomic mass was not the significant player in periodic law
Moseley used X-rays to determine the atomic number of the known elements and then arranged the elements according to increasing atomic number.
Because of Moseley's work, the modern periodic table is based on the atomic numbers of the elements.

8. Summary of Periodic Table Research
Mendeleev - The properties of the elements are a periodic function of their atomic masses.
Moseley - The properties of the elements are a periodic function of their atomic numbers.

9. 6.1
The Periodic Law
In the modern periodic table, elements are arranged in order of increasing atomic number.
In the modern periodic table, the elements are arranged in order of increasing atomic number. Interpreting Diagrams How many elements are there in the second period?

10. 6.1
The Periodic Law
Periodic law - When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
The properties of the elements within a period change as you move across a period from left to right.
The pattern of properties within a period repeats as you move from one period to the next.

11. Periodic Law
Called a “Periodic Table” because many of the physical and chemical properties of the elements repeat in a systematic manner with increasing atomic number.
Periods are the horizontal rows in the table.
Groups are the vertical columns

12. Electron Location Groups
Kernel of an atom is the nucleus and all the electrons except the valence electrons.
Groups
The elements are arranged vertically in columns of the P.T. called Groups or FAMILIES.
Group # indicates the number of valence electrons.
These electrons influence the chemical and physical properties of elements the most.
Certain properties of the elements appear to repeat at regular intervals (periodicity).

13. Electron Location Periods
The elements are arranged horizontally in rows of the P.T. called Periods.
Each period # represents an energy level. Thus locating an element identifies the number of occupied energy levels.

14. Summary
Elements are arranged by increasing atomic number across the periodic table.
Periods are the horizontal rows.
The period # = # of principle energy levels
Elements are grouped vertically by similar chemical and physical properties.
Groups (or Families) are the vertical columns. The group # = # of valence electrons.

15. What are three broad classes of elements?
Three classes of elements are metals, nonmetals, and metalloids.
Across a period, the properties of elements become less metallic and more nonmetallic.

16. Metals, Nonmetals, and Metalloids
Uses of Iron, Copper, and Aluminum
The metals iron, copper, and aluminum have many important uses. How each metal is used is determined by its properties.

17. Metals, Nonmetals, and Metalloids
Uses of Iron, Copper, and Aluminum
The metals iron, copper, and aluminum have many important uses. How each metal is used is determined by its properties.

18. Metals, Nonmetals, and Metalloids
Uses of Iron, Copper, and Aluminum
The metals iron, copper, and aluminum have many important uses. How each metal is used is determined by its properties.

20. Metallic Characteristics
80% of elements are metals
Conduct electricity and heat
Dense
Malleable (bendable to form shapes – jewelry)
Ductile (able to be drawn out into wires)
Lustrous (shiny)
Reactive
High Melting point
Solid at RT

21. Metals Good conductors of heat and electric current.
80% of elements are metals.
Metals have a high luster, are ductile, and are malleable.
Prefer to form cations – loss of electrons to obtain a full valance shell

22. Non-Metals Poor conductors of heat and electricity
In solid form, they are dull and brittle
Usually have lower densities than metals
Many nonmetals (hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine) are diatomic, and most of the rest are polyatomic
Prefer to form anions - gaining electrons to achieve an octet.
Most of the crust, atmosphere and oceans are made up of nonmetals.
Bulk tissues of living organisms are composed almost entirely of nonmetals.
One nonmetal, bromine, is a dark-red liquid.

23. Metalloids Share properties with both metals and nonmetals Solids
Semi-conductors (between a conductor and an insulator)
Form cations or anions. # of valence electrons varies.
The behavior of a metalloid can be controlled by changing conditions.
Less
metallic
metalloid 3A 4A 5A 6A 7A
Poor
Metals
More
metallic
metalloid

24. Were You Paying Attention?
The modern periodic table has elements arranged in order of
colors.
melting and boiling points.
increasing atomic mass.
increasing atomic number.

25. Were You Paying Attention?
Mendeleev arranged the elements in his periodic table in order of increasing
atomic number.
number of protons.
number of electrons.
atomic mass

26. Were You Paying Attention?
Which one of the following is NOT a general property of metals?
ductility
malleability
having a high luster
poor conductor of heat and electricity

27. Squares in the Periodic Table
What type of information can be displayed in a periodic table?
The periodic table displays the symbols and names of the elements, along with information about the structure of their atoms.

28. Squares in the Periodic Table
6.2
Squares in the Periodic Table
Representative Elements
Transition Elements
In this periodic table, the colors of the boxes are used to classify representative elements and transition elements.

29. Alkali Metals The alkali metals are silver-colored
Soft solids (Fr and Cs are liquids)
Group number:
React readily with halogens
React readily with water
One valence electron
so they want to lose an electron and achieve a noble configuration (which is?)
form +1 cations

30. Alkaline Earth Metals Silvery colored Soft solids Group number:
React readily with Group 6
React readily with water (though not as rapidly as the alkali metals)
Two valence electron
so they want to lose 2 electrons and achieve a noble configuration (an octet)
form +2 cations
Beryllium is an exception: It does not react with water

31. Transition Metals Often form colored compounds.
They are often good catalysts
lowers activation energy so rxns are faster
not used up in the rxn
They are silvery-blue at room temperature (except copper and gold) - lustrous.
Malleable
They are solids at room temperature (except Hg)
Good conductors of electricity (Why?)
Partly filled d sublevel
They can have a variety of different charged cations
4s fills before 3d (clouds are more apparent and overlapping occurs)
chromium
Iron
Vanadium
Silver (5s fills before 4f)

32. Lanthanide
Actinide
Silvery-white metals that tarnish when exposed to air
Relatively soft metals
Very reactive
Many rare earth compounds fluoresce strongly under ultraviolet light
All are radioactive
The metals tarnish readily in air
Actinides are very dense metals
Actinides combine directly with most nonmetals

33. Diatomics
Diatomic elements are nonmetal elements that form a covalent bond between two atoms.
“Diatomic 7”
As elements they always travel in pairs of atoms and therefore you must write then as:
H2, N2, O2, F2, Cl2, Br2, I2

34. Halogens Group number: Highly reactive
Due to atoms being one electron short of a full outer shell.
Form -1 anions.
Fluorine is the most reactive element in existence
Form diatomic molecules (F2, Cl2, Br2, I2)
All three states of matter are represented
fluorine and chlorine are gases
bromine is a liquid
iodine and astatine are solids
The name halogen comes from the combination of the Greek word hals, meaning salt, and the Latin word genesis, meaning “to be born.” There is a general class of compounds called salts, which include the compound; table salt. Cl, Br, and I, the most common halogens, can be prepared from their salts.
Both chlorine and bromine are used as disinfectants

35. Noble Gases or Inert Gases
Group number:
Odorless, colorless, monatomic gases.
Stable or unreactive
They have the maximum number of valence electrons their outer shell can hold.
Lighting (Ne), welding and space technology (processes performed under Ar so that no unwanted chem. rx’s occur) .

36. Electron Configurations in Groups
Eddie
Electrons determine properties of elements
Elements can be sorted into noble gases, representative elements, transition metals, or inner transition metals based on their electron configurations.
Electrons play a key role in determining the properties of elements. So there should be a connection between an element’s electron configuration and its location in the periodic table.

37. Electron Configurations in Groups
The Noble Gases
Noble gases - elements in Group 8A of the periodic table. 2
2 – 8
2 – 8 – 8
2 – 8 – 18 – 8
This blimp contains helium, one of the noble gases. Applying Concepts What does the ability of a helium-filled blimp to rise in air tell you about the density of helium?
Ask students what similarities do they notice about the electron configurations of this group of elements.
- The highlighted items identify the highest occupied energy level for each element. Note that the s and p sublevels are completely filled with electrons.
The electron configurations for the first four noble gases in Group 8A are listed below.

38. Electron Configurations in Groups
The Representative Elements
Elements in groups 1A through 7A
Display a wide range of physical and chemical properties.
The s and p sublevels of the highest occupied energy level are not filled.
The group number equals the number of electrons in the highest occupied energy level.

39. Electron Configurations in Groups
In atoms of the Group 4A elements below, there are four electrons in the highest occupied energy level.

40. (classified based on their electron configurations)
Transition Elements
2 Types
(classified based on their electron configurations)
Transition Metals
Group B
Highest occupied s sublevel
Characterized by presence of electrons in d orbitals.
Inner Transition Metals
Lanthanides & actinides
Highest occupied s sublevel
Characterized by presence of electrons in f orbitals

41. Organization of Elements by Electron Configurations
Pattern of blocks
Organized by highest occupied sublevels.
Allows you to predict the electron configuration of an element without knowing it’s number of electrons by its position on the P.T.
The s block contains elements in Group 1A and 2A and the noble gas helium. The p block contains the elements in Groups 3A, 4A, 5A, 6A, 7A, and 8A with the exception of helium. The transition metals belong to the d block, and the inner transition metals belong to the f block.

42. Practice Electron Configurations in Groups
Group 4A
Carbon (C)
Silicon (Si)
Germanium (Ge)
Group 1A
Hydrogen (H)
Lithium (Li)
Sodium (Na)
Potassium (K)

43. Were You Paying Attention?
Which of the following information about elements is usually NOT included in a periodic table?
color
symbol
atomic number
atomic mass

44. Were You Paying Attention?
An alkali metal would have in the highest occupied energy level
an s2 electron.
an s1 electron.
p2 electrons.
p6 electrons.

45. Were You Paying Attention?
Which one of the following is incorrectly labeled?
Ne, noble gas
Cu, transition metal
Ga, transition metal
Cl, halogen

46. Were You Paying Attention?
Transition metals are characterized as being different than representative elements because they have electrons in which suborbitals? p d s f

47. Periodic Trends Atomic radii/ Atomic Size Ions Ionization energy
Ionic size
Electronegativity

48. Trends in Atomic Size
Atomic radius is one half of the distance between the nuclei of two atoms of the same element when the atoms are joined.
This diagram lists the atomic radii of seven nonmetals. An atomic radius is half the distance between the nuclei of two atoms of the same element when the atoms are joined.

49. Trends in Atomic Size
What are the trends among the elements for atomic size?
Atomic size increases from top to bottom within a group and decreases from left to right across a period.

50. Decreases
Increases
Trends in Atomic Size

51. Group Trends in Atomic Size
Drawing Conclusions : Based on the data for alkali metals and noble gases, how does atomic size change within a group?
Predicting: Is an atom of barium, atomic number 56, smaller or larger than an atom of cesium (Cs)?
Analyzing Data: Which alkali metal has an atomic radius of 238 pm?
Question #1: Potassium
Question #2: It increases
Question #3: Smaller, b/c of the amount of data in this graph
As the atomic number increases working across a row(# of protons) , the charge on the nucleus increases and the number of occupied energy levels increases because PEA . The increase in positive charge of the nucleus, pulls the electrons close to the nucleus, decreasing the atomic radius.
Working down a group, the number of occupied energy levels increase, so the shielding effect is greater.

52. Periodic Trends in Atomic Size
Predicting If a halogen and an alkali metal are in the same period, which one will have the larger radius? The alkali metal
As you move across a period, each element has one more proton and one more electron than the preceding element. Across a period, the electrons are added to the same principle energy level. The shielding effect is constant for all the elements in a period. The increasing nuclear charge pulls the electrons in the highest occupied energy level closer to the nucleus and the atomic size decreases. Write this out for students: Working down a group, occupied energy levels increase (getting wider) Working across a period/row, nuclear charge pulls electrons closer.

53. Complete practice problems #30-33.

54. 6.3
Ions
Ion - an atom or group of atoms that has a positive or negative charge.
How do ions form?
Positive and negative ions form when electrons are transferred between atoms.

55. Ions “CAT EYE” Formation of a Cation Loss of e-’s
6.3
Ions
“CAT EYE”
Formation of a Cation
Loss of e-’s
Assume a more “+” charge
Typically metals
When a sodium atom loses an electron, it becomes a positively charged ion. When a chlorine atom gains an electron, it becomes a negatively charged ion. Interpreting Diagrams What happens to the protons and neutrons during these changes?

56. Ions Formation of an Anion Gain of e-’s Assume a more “-” charge
6.3
Ions
Formation of an Anion
Gain of e-’s
Assume a more “-” charge
Typically Nonmetals
When a sodium atom loses an electron, it becomes a positively charged ion. When a chlorine atom gains an electron, it becomes a negatively charged ion. Interpreting Diagrams What happens to the protons and neutrons during these changes?

57. Trends in Ionization Energy
6.3
Trends in Ionization Energy
Ionization energy – the energy required to remove an electron from an atom.
First ionization energy tends to decreases from top to bottom within a group and increases left to right across a period.
The energy required to remove the 1st electron from an atom.
First Ionization Energy??

58. Trends in Ionization Energy
6.3
Trends in Ionization Energy
The energy required to remove an electron from an ion with a 1+ charge is called the second ionization energy.
Ask students: What is it called to remove an electron from an ion with a 2+ charge? Third ionization energy.

59. Removing e-’s from the outer energy level/ shell First
E’s in the outer shells are less strongly held by the nucleus
E’s in the outer shell require less energy to remove then those at lower energy levels

60. Prediction: If you drew a graph for second ionization energy, which element would you have to omit? Explain.
Drawing Conclusions: What is the group trend for first ionization energy for noble gases and alkali metals?
Analyzing Data: Which element in period 2 has the lowest first ionization energy? In period 3?
Question #1: Lithium; sodium
Question #2: First ionization energy decrease as atomic number increases
Question #3: Hydrogen; it has only 1 electron.

61. Trends in Ionization Energy
As the size of the atom increases, nuclear charge has a smaller effect (shielding) on the electrons in the highest occupied energy level. So less energy is required to remove an electron from this energy level and the first ionization energy is lower.
Predicting Which element would have the larger first ionization energy—an alkali metal in period 2 or an alkali metal in period 4?

62. Trends in Ionic Size Trends in Ionic Size Metals form Nonmetals form
6.3
Trends in Ionic Size
Trends in Ionic Size
Metals form
Nonmetals form
RECALL
Cations are always smaller than the atoms from which they form. Anions are always larger than the atoms from which they form.
During reactions between metals and nonmetals, metal atoms tend to lose electrons, and nonmetal atoms tend to gain electrons. The transfer has a predictable effect on the size of the ions that form.

63. Trends in Ionic Size 6.3 Relative Sizes of Some Atoms and Ions
This diagram compares the relative sizes of atoms and ions for selected alkali metals and halogens. The data are given in picometers. Comparing and Contrasting What happens to the radius when an atom forms a cation? When an atom forms an anion?

64. Trends in Ionic Size 6.3 Size generally increases
The ionic radii for cations and anions decrease from left to right across periods and increase from top to bottom within groups.

65. Trends in Electronegativity
6.3
Trends in Electronegativity
Electronegativity - the ability of an atom of an element to attract electrons when the atom is in a compound.
In general, electronegativity values decrease from top to bottom within a group. For representative elements, the values tend to increase from left to right across a period.
Metals have low electronegativity values; more likely to lose e-’s & become a cation
Nonmetals have higher electronegativity values; more likely to gain e-’s & become anions
Electrons are involved in the bonding of elements. The ability for an element to attract an electron will determine what other elements it is likely to bond with.

66. Trends in Electronegativity
6.3
Trends in Electronegativity
Decreases

67. Answer Practice Problems #40-45 in note packet

68. Summary of Trends Nuclear Charge Electronegativity Size of anions
Ionic size
Ionization energy
Shielding
Atomic Size
Size of cations
Decreases
Constant
Increases
Decreases
Increases
Properties that vary within groups and across periods include atomic size, ionic size, ionization energy, electronegativity, nuclear charge, and shielding effect. Interpreting Diagrams Which properties tend to decrease across a period?

69. Were You Paying Attention?
Which of the following sequences is correct for atomic size?
Mg > Al > S
Li > Na > K
F > N > B
F > Cl > Br

70. Were You Paying Attention?
Metals tend to
gain electrons to form cations.
gain electrons to form anions.
lose electrons to form anions.
lose electrons to form cations.

71. Were You Paying Attention?
Which of the following is the most electronegative? Cl Se Na I

72. SOL Review - 16 Questions