1. The Periodic Table
Review Concepts

2. Demetri Mendeleev
By 1860 about 60 elements were known and a method was needed for organization. 
In 1869, Russian chemist Dimitri Mendeleev proposed arranging elements by atomic weights and properties.
The table contained gaps but Mendeleev predicted the discovery of new elements.

4. Important Features Atomic Number Symbol Name Atomic Mass
We’ll learn more about these later…

5. What is the ATOMIC NUMBER?
The number of protons found in the nucleus of an atom Or
The number of electrons surrounding the nucleus of an atom.

6. What is the SYMBOL?
An abbreviation of the element name.

7. What is the ATOMIC WEIGHT?
The number of protons and neutrons in the nucleus of an atom.

8. How do I find the number of protons, electrons, and neutrons in an element using the periodic table?
# of PROTONS = ATOMIC NUMBER
# of ELECTRONS = ATOMIC NUMBER
# of NEUTRONS = ATOMIC _ ATOMIC
WEIGHT NUMBER

10. Elements share traits by FAMILIES (GROUPS) and PERIODS

11. The Elements are Separated into 9 Different Families on the Periodic Table
1. Alkali Metals
2. Alkaline Earth Metals
3. Transition Metals
4. Rare Earth Metals
5. Halogens
6. Noble Gases
7. Metalloids
8. Non-Metals
9. Other Metals

12. FAMILIES : Alkali Metals
Very reactive metals that do not occur freely in nature
Often found in salts
Malleable, ductile, good conductors of heat and electricity.
Can explode if they are exposed to water

13. FAMILIES : Alkaline Earth Metals
Very reactive
Not found free in nature

14. FAMILIES : Transition Metals
Ductile And malleable, and conduct electricity and heat
Iron, cobalt, and nickel, are the only elements known to produce a magnetic field

15. FAMILIES : Rare Earth Metals
Many are man-made

16. FAMILIES : Halogens
"Halogen" means "salt-former" and compounds containing halogens are called "salts"
Exist in all three states of matter
Usually bond with alkali metals to form basic salts

17. FAMILIES: Noble Gases
Unreactive
Inert Elements

18. Metalloids have Properties of both metals and non-metals
Some of the metalloids are semi- conductors. This means that they can carry an electrical charge under special conditions. This property makes metalloids useful in computers and calculators (“Silicon Valley”)

19. Non-Metals Not able to conduct electricity or heat very well
Very brittle
Do not reflect light

20. Other Metals Ductile and Malleable Many are man-made
Solid with a relatively high density
Opaque

21. Metals Non-Metals Metalloids To Summarize:
They are solid (except Mercury)
They are shiny, good conductors of electricity and heat.
They are ductile and malleable
Metals
Brittle (not malleable or ductile)
Poor conductors of both heat and electricity
Non-Metals
Contain properties of both metals and non-metals
Metalloids

22. Other Trends: Reactivity