1. Chapter 5 – The Periodic Table

2. the Father of Modern Chemistry
5.1 Organizing the Elements
Antoine Lavoisier ( )
the Father of Modern Chemistry
In 1789, he grouped the elements into categories
metals
nonmetals
gases
earths
for 80 years scientists tried to classify elements, but no one way accounted for the variety of elements known

3. by the 1860’s, there were 63 known elements
5.1 Organizing the Elements
Dmitri Mendeleev ( )
a chemist and teacher
by the 1860’s, there were 63 known elements
used the game of solitaire as the inspiration for his organization of the elements

4. on each card, he listed the element’s name, mass and properties
5.1 Organizing the Elements
on each card, he listed the element’s name, mass and properties
lined up cards in rows in order of increasing mass
kept elements with similar properties in the same column
the chart was periodic (repeating)

5. 5.1 Organizing the Elements
periodic table – an arrangement of elements in columns, based on a set of properties that repeat from row to row

6. ? 5.1 Organizing the Elements 1 2 3 4
Which dot should replace the question mark? 1 2 3 4

7. Mendeleev left gaps in the table
5.1 Organizing the Elements
Some elements would not fit in certain spots because they didn’t have the right mass and / or properties
Mendeleev left gaps in the table

8. Named a predicted element “eka-aluminum”
5.1 Organizing the Elements
Mendeleev went on to give names to elements he predicted would be discovered and fill in the blanks
Named a predicted element “eka-aluminum”
Later an element was discovered that matched the properties of eka-aluminum. (named Gallium)
With a periodic table the chemical behavior of elements can be explained and predicted

9. 5.2 The Modern Periodic Table
In the modern periodic table, elements are arranged by increasing atomic number (number of protons)

10. each row is called a period
5.2 The Modern Periodic Table
each row is called a period
the number of elements per period varies because the number of available orbitals varies

11. each column is called a group
5.2 The Modern Periodic Table
each column is called a group
the elements within a group have similar properties
the pattern of repeating properties is the periodic law

12. H 1 atomic number Hydrogen 1.0079 element symbol element name
5.2 The Modern Periodic Table
atomic number H
Hydrogen 1
1.0079
element symbol
element name
atomic mass
atomic mass unit (amu) – one twelfth the mass of a carbon-12 atom

13. Distribution of Chlorine
5.2 The Modern Periodic Table Cl
Chlorine 17
35.453
What is the atomic mass of chlorine?
amu
Distribution of Chlorine
Isotopes in Nature
Isotope
Percentage
Atomic Mass
Chlorine-35
75.78%
34.969
Chlorine-37
24.22%
36.966
the atomic mass is a weighted average of these values

14. 5.2 The Modern Periodic Table

15. elements are first classified as solids, liquids, or gases
5.2 The Modern Periodic Table
elements are first classified as solids, liquids, or gases

16. elements are then classified as to whether or not they occur naturally
5.2 The Modern Periodic Table
elements are then classified as to whether or not they occur naturally
all but two elements in the first 92 elements occur naturally

17. then classified as metals, nonmetals, and metalloids
5.2 The Modern Periodic Table
then classified as metals, nonmetals, and metalloids

18. most of the elements are metals
5.2 The Modern Periodic Table
most of the elements are metals
- good conductors
- malleable and ductile
- solid at room temperature (except Mercury)
- some very reactive

19. transition metals are groups 3 through 12
5.2 The Modern Periodic Table
transition metals are groups 3 through 12
tend to form compounds with distinctive colors

20. other elements are called nonmetals
5.2 The Modern Periodic Table
other elements are called nonmetals
- poor conductors
- the solids are brittle
- many are gases at room temperature
- some are reactive, some aren’t

21. and still other elements are called metalloids
5.2 The Modern Periodic Table
and still other elements are called metalloids
- properties of metals and nonmetals
- conductivity varies with temperature

22. 5.2 The Modern Periodic Table
elements become less metallic and more nonmetallic going across a period from left to right

23. 5.2 The Modern Periodic Table
How did some ancient civilizations preserve their dead?
What are two types of information that scientists discover by examining mummies?
What evidence led forensic scientists to suspect Tutankhamen, also known as King Tut, might not have died from natural causes?
List features that scientists found in the bones of mummies in Chile.
What do forensic scientists suspect to be the causes of the features found in these mummies?

24. 5.3 Representative Groups
Is hydrogen a metal?
It is not. Why, then, is it grouped with the metals in the periodic table?
It shares an electron configuration similar to other elements in Group 1

25. valence electron – an electron in the highest energy level of an atom
5.3 Representative Groups
The number of the A groups tells the number of valence electrons in an atom.
valence electron – an electron in the highest energy level of an atom
Elements in groups share properties because they have the same number of valence electrons

26. 5.3 Representative Groups
In class assignment to be collected and graded:
Read pages Each section discusses one of the A-groups on the periodic table. You are to do the following on a separate sheet(s) of notebook paper. All your pages are to be stapled and collected when you are finished.
Put a heading for each new section, it should contain both the A-Group name and number. Under each heading put:
The number of valence electrons
A list of the elements within the group (both name and symbol)
A comment on the reactivity of the elements within the group
Two elements or compounds containing the elements from the group and how they are used.
Two questions you formulate about each group based on what you have read.
When finished, do the questions on page (complete sentences)

27. Group 1A – Alkali Earth Metals
5.3 Representative Groups
Group 1A – Alkali Earth Metals
One valence electron
Found in nature as compounds
Reactivity increases going from top to bottom of group
Many react violently with water
Very soft (can cut with a knife)
Video 1
Video 2
Video 3
Video 4
Video 5
Video 6

28. Group 2A – Alkaline Earth Metals
5.3 Representative Groups
Group 2A – Alkaline Earth Metals
Two valence electrons
Harder than Group 1A elements

29. Three valence electrons
5.3 Representative Groups
Group 3A – Boron Family
Three valence electrons
Aluminum is the most abundant metal in the Earth’s crust

30. Four valence electrons Get more metallic as go down group
5.3 Representative Groups
Group 4A – Carbon Family
Four valence electrons
Get more metallic as go down group
Most compounds in the body contain carbon (the exception is H2O)
Silicon is the 2nd most abundant element in the Earth’s crust

31. Group 5A – Nitrogen Family
5.3 Representative Groups
Group 5A – Nitrogen Family
Five valence electrons
78% of the atmosphere is nitrogen

32. Oxygen is the most abundant element in the Earth’s crust
5.3 Representative Groups
Group 6A – Oxygen Family
Six valence electrons
Oxygen is the most abundant element in the Earth’s crust
Sulfur was one of the first element’s discovered

33. Seven valence electrons All are highly reactive
5.3 Representative Groups
Group 7A – The Halogens
Seven valence electrons
All are highly reactive
Fluorine the most reactive, Chlorine a close second
React with metals to form compounds called salts

34. Group 8A – The Noble Gases
5.3 Representative Groups
Group 8A – The Noble Gases
Eight valence electrons, except Helium (has 2)
Colorless, odorless
Extremely unreactive
Used in “neon” lighting

35. 5.3 Representative Groups