1. The Periodic Table
Chapter 5

2. Dmitri Mendeleev Russian chemist
Created first adopted periodic table in the 1860’s

3. Mendeleev's Table Arranged elements in order of increasing mass
Divided columns -elements with similar properties were in the same column
Left gaps in the table for future discoveries

4. Atomic Mass Unit Average mass of an element and all of its isotopes
Uses weighted averages
All based around the standard of Carbon-12
Can change as new isotopes are discovered

5. Changes to Mendeleev's Table
Periodic Law
Elements are arranged by increasing atomic number since they NEVER change

6. Columns Referred to as groups or families
Elements in the same column (1A etc.) behave in the same way
Each column has same number of Valance electrons

7. Rows Called periods 7 total
Period 1 is the top row and period 7 is the bottom row
The number of the period = energy levels (rings)

8. Colors on the Table The colors indicate different types of elements
Table can be broken down into 3 sections
Metals
Non-metals
Metalloids

9. Non-Metals 17 elements Poor conductors of heat and electricity
Many are gases at room temp
If solid, brittle
Right side of table plus H

10. Non-Metals Some non-metals are very reactive
Fluorine**, Chlorine, Oxygen
Most reactive nonmetals are in column 7
Some are NOT reactive at all
All of column 8

11. Metalloids Have properties of both metals and non-metals
Semiconductors
Ability of conductor varies at temperature
Location - 5,14,32,51,84 to the right

12. Metals Good conductors Solids (except for Hg) Mostly malleable
Some are reactive some are not
Most reactive are in column 1
Location – Left side of the periodic table

13. Variations Across a Period
Left to Right: Elements become less metallic and more nonmetallic
Right to Left: Elements become more reactive for metals
Left to Right: Elements become more reactive for nonmetals

14. Groups Column 1A or IA (H-Fr) Alkali metals 1 valence e-
Highly reactive
Increase reactivity as you go down the family
So reactive that they are hard to store

15. Column 2A or IIA Be-Ra Alkaline Earth Metals 2 valence e-
Called Alkaline Earth Metals because they are materials often found in the Earth.

16. Column 3A or IIIA B-Tl Boron Family 3 valence e-
Aluminum is the most abundant metal on earth

17. Column 4A or IVA C – Pb Carbon Family 4 valance e-
Carbon is the most abundant element in your body

18. Column 5A or VA N – Bi Nitrogen Family 5 valence e-
N and P are used in fertilizers (help plants grow)

19. Column 6A or VIA O-Po Oxygen Family 6 valence e-
Oxygen is most abundant element in the earth’s crust

20. Column 7A or VIIA F-At Halogens 7 valence e Most reactive nonmetals
All have similar chemical properties, not physical properties

21. Column 8A or VIIIA He-Rn Noble Gases
Will not react with other elements
8 valence e-
Used in neon signs and with elements that react with water

22. Transition Metals All the middle (1B – 8B)
Form compounds with distinctive colors
Separate 2 rows
Called Rare Earth Metals
Very similar to each other