1. SCH3U Unit 1: Matter, Chemical Trends and Chemical Bonding
The PERIODIC TABLE
SCH3U
Unit 1: Matter, Chemical Trends and Chemical Bonding

2. The History of the Periodic Table
Chemists have arranged elements based on observed properties for nearly 200 years.
Johann Dobereiner (1829): “The Law of Triads”
Observed similar properties and atomic masses in groups of 3 elements
Inconsistencies arose as more elements were discovered

3. The History of the Periodic Table
John Newlands (1865): “The Law of Octaves”
Arranged elements by atomic mass and observed similar properties in every 8th element

4. The History of the Periodic Table
Julius Lothar Meyer (1864):
Arranged 28 elements by atomic mass and recognized periodic patterns

5. The History of the Periodic Table
Dmitri Mendeleev (1869): “Periodic Law”
Had a similar, independent approach to Meyer
Arranged cards of elements with their properties written on them in order of atomic mass and recognized periodic patterns
He attributed gaps to undiscovered elements

6. The History of the Periodic Table
Henry Moseley (1912): “Atomic Number”
Determined the atomic number of elements experimentally
This has been a major contribution to the modern periodic table

7. The Modern Periodic Table
Modern Periodic Law:
When elements are arranged by atomic number, their chemical and physical properties recur periodically

8. The Modern Periodic Table

9. The Periodic Table
The periodic table arranges elements in such a way that elements with similar properties are grouped together.

10. The Periodic Table Groups (families): Periods:
vertical columns, numbered 1 through 18 (IA to VIIIA and IB to VIIIB)
Periods:
horizontal rows (there are 7 periods)

11. The Periodic Table Main group elements: groups 1,2, 13-18 (IA – VIIIA)
Transition metals: groups 3-12 (IB – VIIIB)
Inner transition metals: the two separate rows at the bottom of the periodic table.
Lanthanides
Actinides

12. Metals and Non-metals
The “staircase” separates the metals and non-metals on the periodic table
The staircase runs from the top of Group 13 to the bottom of 17
Metals are to the left of the staircase
The non-metals are to the right
Metalloids (semi-metals) are found along the staircase line

13. Groups (Families)
Group 1 - Alkali metals: react with water to form alkaline (basic) solutions
Group 2 – Alkaline earth metals: react with oxygen to form compounds known as oxides (which can further react to form alkaline (basic) solutions)
Group 17 – Halogens: combine with other elements to form salts
Group 18 – Noble gases: do not combine naturally with any other elements.

14. The Periodic Table

15. The Periodic Table

16. Circular Periodic Table

17. Pyramidal Periodic Table