1. The Periodic Table—Categories (Chapter 6)

2. Dmitri Mendeleev
1869
Arranged known (63) elements by increasing atomic mass
Also grouped by similarities (physical properties, what they react with, etc)

3. Henry Moseley
My hero
Father of Modern Periodic Table (50 yrs after Mendeleev’s Table)
Arranged elements by atomic number (after discovery of protons/neutrons/electrons) and chemical properties
Studied under Rutherford

4. Parts of the Periodic Table:
Period – describes a horizontal row on the Periodic Table
Group / Family – describes a vertical column on the Periodic Table

5. What do these parts tell us?
Periods represent the number of energy levels in the atom
Groups represent the typical number of valence electrons in the outer most energy level (representative elements only!)
Groups are arranged according to similar chemical properties

6. Where are the…
Metals found? (To the left of the metalloid line, exception: H)
Nonmetals found? (To the right of the metalloid line)
Metalloids found? (Touching the metalloid line. Exception: Aluminum)

7. What are metals, nonmetals, metalloids?
Metals: Elements that tend to lose electrons when forming ions, usually solid at room temp
Nonmetals: Elements that tend to gain electrons when forming ions, usually gas at room temp
Metalloids: Elements that either gain or lose electrons when forming ions, solid at room temp

8. Representative Elements
Transition Elements
Groups 1,2,13-18
Consist of elements that show a wide range of chemical and physical properties
Referred to as group “A”
Could have unfilled s or p sublevels in their highest energy level
Groups 3-12
Consist of elements that connect representative elements
Referred to as Group “B”
Could have unfilled d or f sublevels in their highest energy level

9. Let’s identify the following groups:
Alkali Metals
Alkaline Earth Metals
Transition Metals
Boron Group
Carbon Group
Nitrogen Group
Oxygen Group
Halogens
Noble Gases
Lanthanide Series
Actinide Series