1. The Periodic Table
Chapter 5 Section 1

2. Mendeleev’s Table
Dmitri Mendeleev published the first version of the periodic table
This table was arranged in increasing atomic mass
Elements with similar properties fell into groups
Why do you think there were gaps in his table?

3. Moseley
Improved Mendeleev’s table by arranging the elements In order of increasing number of protons

4. Today’s Table Organized by increasing atomic number
Remember that atomic number is the number is the number of protons
A period is a row of elements, the properties change gradually
A group or a family is a column of elements, they have the same chemical or physical properties
How does reading across a period of the periodic table compare with reading down a group of the table?

5. More organization
Representative Elements Are groups 1 and 2 and groups We will get into this more in Section 2
Transition Elements Groups 3-12, these are all metals
The elements below are called Lanthanide and actinide series, they are moved to the bottom to save space on the chart

6. Metals Except Mercury all metals are solid
Have luster—the ability to reflect light
Are good conductor of heat and electricity
Are malleable or can be shaped
And ductile- can be turned into wire, thin and still be able to bend without breaking

7. Nonmetals Are usually gases or very brittle solids
Poor conductors of heat and electricity
Carbon, sulfur, nitrogen, phosphorus, oxygen and iodine are all essential for life

8. Metalloids Elements that share some properties of metals and nonmetals
Can be used as a semiconductor of electricity or heat
What would you expect the insulation around an outlet be made out of, a metal, a nonmetal, or a metalloid? Why.

9. Symbols of the Table
The symbols are one or two letter abbreviations, the first letter is always capital, so yours should be too!
Often it is based on the element name, which makes it easy.
Sometimes the symbol might come from the Greek or Latin name for example, Leads symbol is Pb or Plumbum