1. “The Periodic Table”

2. Mendeleev’s Periodic Table
By the mid-1800s, about 70 elements were known to exist
Dmitri Mendeleev – a Russian chemist and teacher
Arranged elements in order of increasing atomic mass
Thus, the first “Periodic Table.”

3. Horizontal rows = periods There are 7 periods
The Periodic Law says:
Horizontal rows = periods
There are 7 periods
Same number of energy levels
Vertical column = group (or family) There are 18 groups.
Similar physical & chemical prop.
Identified by number & letter (IA, IIA)

4. Areas of the periodic table
Three classes of elements are:
1)metals,
2)nonmetals, and
3)metalloids
Metals: electrical conductors, have luster, ductile, malleable. Are on the left side of the periodic table.
Nonmetals: generally brittle and non-lustrous, poor conductors of heat and electricity

5. Areas of the periodic table
Some nonmetals are gases (O, N, Cl); some are brittle solids (S); one is a fuming dark red liquid (Br)
Are on the right side of the periodic table
Notice the heavy, stair-step line?
Metalloids: border the line-2 sides
Properties are intermediate between metals and nonmetals
Live on or below the bold line

6. A. Metallic Character
Metals
Nonmetals
Metalloids

7. Squares in the Periodic Table
The periodic table displays the symbols and names of the elements, along with information about the structure of their atoms:
Atomic number and atomic mass
Black symbol = solid; red = gas; blue = liquid
(from the Periodic Table on our classroom wall)

8. Groups of elements - family names
Group IA – alkali metals
Forms a “base” (or alkali) when reacting with water (not just dissolved!)
have 1 electron in their outermost shell
Group 2A – alkaline earth metals
Also form bases with water; do not dissolve well, hence “earth metals”
have 2 electrons in their outermost shell
Group 3A – boron family
have 3 electrons in their outermost shell
Group 4A – carbon family
have 4 electrons in their outermost shell

9. Groups of elements - family names
Group 5A – nitrogen family (pnitogen)
have 5 electrons in their outermost shell
Group 6A –oxygen family
have 6 electrons in their outermost shell
Group 7A – halogens
Means “salt-forming”
have 7 electrons in their outermost shell
Group 8A – noble gases
Have 8 electrons in their outermost shell

11. Electron Configurations in Groups
Elements can be sorted into 4 different groupings based on their electron configurations:
Transition metals
Filling D orbital
Inner transition metals
Filling F orbital
Representative elements
Filling S or P orbital
Noble gases
FULL outer orbital