1. The Periodic Table

3. The Father of the Periodic Table
Dimitri Mendeleev was the first scientist to notice the relationship between the elements
Arranged his periodic table by atomic mass
Said properties of unknown elements could be predicted by the properties of elements around the missing element

4. A Correction to the Periodic Table
Henry Moseley later discovered that the periodic nature of the elements was associated with atomic number, not atomic mass
The current table is arranged by atomic number.

5. Column = Group or Family
The Periodic Table
Column = Group or Family
18 columns on the Periodic Table
Row = Period
7 rows on the Periodic Table

6. What does the information in the box tell me?1 H
Hydrogen
1.008
Atomic Number = # of protons # of electrons
Elemental Symbol
Atomic Mass
= # of protons neutrons

7. Organization of the Periodic Table
Organized by Atomic Number
Metals
Non Metals
Metalloids
Groups (Columns/Families)
Periods (Rows)

8. Metals, Nonmetals, and Metalloids
Only
nonmetal on the metal side
Nonmetals are on the right of the stair-step
Semi-metals, “metalloids,” touch the stair-step
Metals are to the left of the stair- step

9. GROUPS/Family Elements in the same group behave in similar ways
Each column is called a “group/Family”
Groups have SIMILAR PROPERTIES
Elements in the same group behave in similar ways
The group that an element is in tells you how many valence electrons it has.
This means that they have the same number of electrons in the outermost shell.

10. The Groups of the Periodic Table
Group 1: The Alkali Metals
Most reactive metals on the PT
Rarely found free in nature
Charge of 1
1 valence electron
Group 2: The Alkaline Earth Metals
Still quite reactive
Charge of 2
2 valence electrons

11. The Groups of the Periodic Table
Groups 3-12: Transition Metals
Found freely and in compounds in nature
Charge is usually 2 but can vary
Usually 2 valence electrons
Group 13: Boron Family
Charge is 3
3 valence electrons

12. The Groups of the Periodic Table
Group 14: The Carbon Family
Contains elements that can form unusual bonds (carbon and silicon)
Charge is +4 or -4
contains 4 valence electrons
Group 15: The Nitrogen Family
Charge is -3
contains 5 valence electrons

13. The Groups of the Periodic Table
Group 16: The Oxygen Family
Also known as the chalcogens
Charge is -2
6 valence electrons
Group 17: The Halogens
Most reactive nonmetals
charge is -1
7 valence electrons
Group 18: The Noble Gases (The Inert Gases)
Nonreactive
Charge is 0
2 or 8 valence electrons

14. Periods (Rows)
The period an element is in indicates how many “shells” it has around it.

15. Special Rows on the PT—Transition
Lanthanides
Actinides
*The Lanthanides & Actinides together are called the Inner Transition Elements.