1. The Periodic Table & Element Classes

2. The Periodic Table is the organization of known elements arranged by increasing atomic number (# of protons).
This design was based on research by Henry Moseley (23 November 1887 – 10 August 1915)

3. The first periodic table was created by Dmitri Mendeleev a Russian chemist and inventor.
Using the table he predicted the properties of elements yet to be discovered!

4. Group or Family
Period

5. CA Standards
Students know how to use the periodic table to identify alkali metals, alkaline earth metals, transition metals, metals, semimetals (metalloids), nonmetals, halogens and noble gases.

6. Metals

7. Properties of Metals Shiny—metallic luster
Malleable—can be hammered or rolled into sheets
Ductile—can be stretched into fine wires
Tensile strength— resists breaking
Most are solid at room temperature (except mercury)
Good conductors of electricity and heat

8. Alkali Metals

9. Potassium, K reacts with water and must be stored in kerosene
Alkali Metals
NEVER found pure in nature because they are too reactive
Reactivity of these elements increases down the group
Group 1= Have 1 valence electron
Potassium, K reacts with water and must be stored in kerosene

10. Alkaline Earth Metals

11. Alkaline Earth Metals less reactive than alkali metals
not found pure in nature; they are too reactive
The word “alkaline” means “basic”
common bases include salts of the metals
Ca(OH)2
Mg(OH)2
Group 2 = 2 valence electrons

12. Transition Metals

13. Transition Metals (still a metal just transitioning to non-metal)
Copper, Cu, is a relatively soft metal, and a very good electrical conductor.
Mercury, Hg, is the only metal that exists as a liquid at room temperature

14. Metaloides

15. Properties of Metalloids
have properties of both metals and nonmetals.
more brittle than metals, less brittle than most nonmetallic solids
semiconductors of electricity
Some metalloids possess metallic luster

16. Silicon, Si – A Metalloid
Silicon has metallic luster
Silicon is brittle like a nonmetal
Silicon is a semiconductor of electricity
Other metalloids include:
Boron, B
Germanium, Ge
Arsenic, As
Antimony, Sb
Tellurium, Te

17. Nonmetals

18. Nonmetals- 20% of elements
Brittle
Gases at room temperature (except: bromine= liquid, iodine, sulfur, selenium, phosphorus &carbon are all solid)
Poor conductors of electricity and heat
HYDROGEN is a nonmetal
Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element.

19. Examples of Nonmetals
Microspheres of phosphorus, P, a reactive nonmetal
Sulfur, S, was once known as “brimstone”
Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure

20. Halogens never found pure in nature; they are too reactive
in their pure form are diatomic molecules (F2, Cl2, Br2, and I2)
Group 7= 7 valence electrons
Chlorine is a yellow-green poisonous gas

21. Noble Gases

22. Noble Gases
They are ONLY found pure in nature – they are chemically unreactive!!
Colorless, odorless and unreactive; they were among the last of the natural elements to be discovered
Group 8 = 8 valence electrons (except helium, which has only 2)

23. Homework—Due Tuesday 9/20
Complete Periodic Table Activity
Matter and Change Review Worksheet
Chapter 1 Quiz

24. Periodic Table Coloring
Get colored pencils from the back and open your book to pg 17.
Color and label each section of the periodic table that we discussed today.
Make a key at the top of your chart.