1. Periodic Table of the Elements
A Chemist’s “Cheat Sheet”

2. Development of the Periodic Table
Dmitri Mendeleev – “Father of the Periodic
Table”
Russian Chemist who
developed the 1st
periodic table in the
late 1800’s

3. Mendeleev’s First Table (1872)
Elements were arranged according to increasing atomic mass
Knew other elements existed and left spaces for them

4. An Improved Periodic Table
Henry Moseley - British scientist who improved
Mendeleev’s table (1911)
Arranged the elements by
increasing atomic number
Killed in WWI at age 28

5. How it all fits together

6. Modern Periodic Table Glenn Seaborg (1912-1999)- American scientist
Who arranged modern table in 1941
Placed the lanthanide/actinide
series at the bottom of the table
Discovered elements 94 to 102
In 1951 was awarded the
Nobel Prize in chemistry
Element 106 named in his honor

7. Periodic Trends
Elements are arranged into horizontal rows called PERIODS
Elements within a period have the same number of energy levels
1 energy level
2 energy levels
3 energy levels
7 energy levels
6 energy levels
5 energy levels
4 energy levels

8. Elements are arranged in vertical columns called a GROUP or FAMILY
Elements in the same family have the same number of valence electrons and share similar CHEMICAL properties
4 valence electrons
6 valence electrons
2 valence electrons
1 valence electron
3 valence electrons
5 valence electrons
7 valence electrons
(except He but all have full outer shells)
8 valence electrons

9. Electrons VALENCE ELECTRONS - found in the outermost energy level
Determine an element’s chemical properties
If the atom has a full outer shell, it is NON-REACTIVE!!
Which group of elements is non-reactive?
Noble gases

10. Periodic Trends N O R E A C T I V

11. Metals and Non-Metals

12. Metal Properties Shiny solids Ductile (able to be stretched)
Malleable (able to be shaped)
Good conductors of heat and electricity

13. Nonmetal Properties May be solids, liquids or gases
Dull, brittle solids
Poor conductors of heat and electricity

14. Metalloid Properties
Nonmetals with properties of both metals and non-metals
Weak conductors of heat and electricity
Solids that can be shiny or dull
Ductile and malleable

15. Families of Elements Alkali Metals
Group 1, highly reactive, 1 valence electron
Explosive with water

16. Families of Elements Alkaline Earth Metals
Group 2, reactive, 2 valence electrons
Hard and shiny, high melting points

17. Families of Elements Transition Metals Group 3-12
Complex electron arrangements

18. Families of Elements Halogens
Group 17, highly reactive, 7 valence electrons

19. Families of Elements Noble Gases
Group 18, full outer shells (2 in He and 8 in others)
NON-REACTIVE

20. Families of Elements Rare Earth Elements Group 3, Period 6 and 7
Special group of transition metals

21. Families of Elements Metalloids
Non-metal elements that are conductors of heat and electricity

22. ELEMENTS!!!!!!!!
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