1. Chapter 12 Material on Midterm
The Periodic Table
Chapter 12
Material on Midterm

2. Section 1: Arranging the Elements
Objectives
Describe how Mendeleev arranged elements in the first periodic table
Explain how elements are arranged in the modern periodic table
Compare metals, nonmetals, and metalloids base on their properties and on their location in the periodic table
Describe the difference between a period and a group

3. Section 1: Arranging the Elements
Placement Pattern
What is the best way to arrange things?

4. Section 1: Arranging the Elements
Discovering a Pattern
Mendeleev discovered that the elements discovered had a pattern to them

5. Section 1: Arranging the Elements
Mendeleev arranged atoms by increasing atomic mass
Saw that there was a periodic trend
Periodic describes something that occurs or repeats at regular intervals
Organized them in a table
FIRST PERIODIC TABLE OF THE ELEMENTS
Some holes in the table

7. Section 1: Arranging the Elements
Predicting Properties of Missing Elements
Some gaps in the pattern
Was able to predict the properties
Eka-aluminum….after aluminum
Mendeleev’s Predicted Eka-aluminum (1871)
Discovered Germanium (1886)
Atomic mass 70
72.6
Density
5.5 g/cm3
5.3 g/cm3
Appearance
Dark gray metal
Gray metal
Melting point
High melting point
937 C

8. Section 1: Arranging the Elements
Changing the arrangement
Moseley realized it made more sense to use the atomic number instead of the atomic mass
The periodic law is the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements

9. Section 1: Arranging the Elements
The Periodic Table and Classes of Elements
We break elements into three major groups
Metals
Nonmetals
Metalloids

10. Section 1: Arranging the Elements
Metals
Most elements
Left of the zigzag line on the periodic table
Most are solid at room temperature (Hg exception)
Properties
Shiny
Malleable
Ductile
Good conductors

11. Section 1: Arranging the Elements
Nonmetals
Right of the zigzag line
Many are gases at room temperature
Not malleable
Not ductile
Not shiny
Poor conductors

12. Section 1: Arranging the Elements
Metalloids
Aka semiconductors
Border zigzag line
Have some properties of metals
Some properties of nonmetals

13. Section 1: Arranging the Elements
Decoding the Periodic Table

14. Section 1: Arranging the Elements
Horizontal
A period is a horizontal row of elements on the periodic table
Properties repeat as you go along a period
Vertical
A group is a vertical column of elements in the periodic table
Elements in a group share chemical properties

15. Section 1: Arranging the Elements
Section Review
Please answer the objectives on your objective summary sheet
Describe how Mendeleev arranged elements in the first periodic table
Explain how elements are arranged in the modern periodic table
Compare metals, nonmetals, and metalloids base on their properties and on their location in the periodic table
Describe the difference between a period and a group

16. Section 2: Grouping the Elements
Objectives
Use the periodic table to gain information about various elements
Explain why elements in a group often have similar properties
Describe the properties of the elements in the groups of the periodic table

17. Section 2: Grouping the Elements
We will discuss the following groups:
Group 1: Alkali Metals
Group 2: Alkaline Earth Metals
Groups 3-12: Transition Metals
Group 13: Boron Group
Group 14: Carbon Group
Group 15: Nitrogen Group
Group 16: Oxygen Group
Group 17: Halogens
Group 18: Noble Gases
Hydrogen

18. Section 2: Grouping the Elements
Group 1: Alkali Metals
The alkali metals are the elements of Group 1 of the periodic table (lithium, sodium, potassium, rubidium, cesium, and francium)
Group contains: metals
Electrons in outer level: 1
Reactivity: Very reactive
Other shared properties: softness, color of silver, shininess, low density

20. Section 2: Grouping the Elements
Group 2: Alkaline Earth Metals
The alkaline earth metals are the elements of Group 2 of the period table (beryllium, magnesium, calcium, strontium, barium, and radium)
Group contains: metals
Electrons in outer level: 2
Reactivity: very reactive, but less reactive than alkali metals
Other shared properties: color of silver, higher densities than alkali metals

22. Section 2: Grouping the Elements
Groups 3-12: Transition Metals
No individual names
Varied in properties
Group contains: metals
Electrons in outer level: 1 or 2
Reactivity: less reactive than the alkaline earth metals
Other shared properties: shininess, good conductors, higher densities and melting points than Groups 1 and 2 (except Hg)

24. Section 2: Grouping the Elements
Lanthanides and Actinides
The two bottom rows
Row 1: starts with lanthanum--lanthanides
Shiny, reactive metals
Row 2: starts with actinium—actinides
Radioactive, unstable elements
Any after 94—not found naturally

25. Section 2: Grouping the Elements
Group 13: Boron Group
The Boron Group contains elements from group 13 of the periodic table (boron, aluminum, gallium, indium, and thallium)
Group contains: one metalloid and four metals
Electrons in the outer level: 3
Reactivity: reactive
Other shared properties: solids at room temperature

27. Section 2: Grouping the Elements
Group 14: Carbon Group
The carbon group contains elements from group 14 of the periodic table (carbon, silicon, germanium, tin, lead, flerovium)
Group contains: one nonmetal, two metalloids, and three metals
Electrons in the outer level: 4
Reactivity: varies among the elements
Other shared properties: solids at room temperature

28. Section 2: Grouping the Elements
Carbon: nature’s most important element
Found in carbohydrates, proteins, fats, and nucleic acid (DNA)
Germanium and silicon are used as conductors in computer chips

29. C Si Ge Sn Pb

30. Section 2: Grouping the Elements
Group 15: Nitrogen Group
The Nitrogen group contains elements from group 15 of the periodic table (nitrogen, phosphorus, arsenic, antimony, bismuth, ununpentium)
Group contains: two nonmetals, two metalloids, and two metals
Electrons in the outer level: 5
Reactivity: varies among the elements
Other shared properties: solids at room temperature (except for nitrogen)

32. Section 2: Grouping the Elements
Group 16: Oxygen Group
The Oxygen group contains elements from group 16 of the periodic table (oxygen, sulfur, selenium, tellurium, polonium, livermorium {name pending})
Group contains: three nonmetals, one metalloid, and two metals
Electrons in the outer level: 6
Reactivity: reactive
Other shared properties: all but oxygen are solid at room temperature

34. Section 2: Grouping the Elements
Group 17; Halogens
The halogens are elements of group 17 of the periodic table (fluorine, chlorine, bromine, iodine, astatine, ununseptium); halogens combine with most metals to form salts
Group contains: nonmetals
Electrons in the other level: 7
Reactivity: very reactive
Other shared properties: poor conductors, violent reactions with alkali metals to form salts, never in uncombined form in nature

36. Section 2: Grouping the Elements
Group 18: Noble Gases
The noble gases are elements of group 18 of the periodic table (helium, neon, argon, krypton, xenon, radon, and ununoctium); noble gases are unreactive
Group contains: nonmetals
Electrons in the outer level: 8 (except helium, which has 2)
Reactivity: unreactive
Other shared properties: colorless, odorless gases at room temperature

38. Section 2: Grouping the Elements
Hydrogen
The properties of hydrogen do not match any other group (the loner element)
We stick him in group 1 based on outer electrons
Electrons in outer level: 1
Reactivity: reactive
Other properties: colorless, odorless gas at room temperature; low density, explosive reactions with oxygen

39. Section 2: Grouping the Elements
Section Review
Please answer the objectives on your objective summary sheet
Use the periodic table to gain information about various elements
Explain why elements in a group often have similar properties
Describe the properties of the elements in the groups of the periodic table