1. The Periodic Table of Elements (Ch.1)
Organized by Dimitri Ivanovitch Mendeleev in 1869
The purpose was to classify elements based on their (common) physical and chemical properties, and behaviours (more than 60 elements!)
There are different ways that elements are classified in the table:
Periods and Groups
Solids, liquids, gases
Metals, nonmetals, metalloids
The periodic table song!

2. Dimitri Ivanovitch Mendeleev (2.1)
Russian chemist! – Father of the periodic table

3. Metals
Generally good conductors of electricity and heat. They are both ductile and malleable and shiny. All are solid at room temperature except mercury which is a liquid. Many metals will react with acids. In the periodic table, they are found to the left of the staircase. Galium -

4. Nonmetals
Generally, they are poor conductors of eletricity and heat. Many of them are gases at room temperature. In the periodic table, they are found to the right of the staircase, except hydrogen, which is traditionally placed above the first column of the table.

5. Metalloids
Seven elements with properties of both metals and nonmetals. For that reason, they are used to make semiconductors, important materials for transitors, circuits and laser. Found along the staircase.

6. Classification 1: Periods & Groups (2.2)
Columns on the Periodic Table are referred to as groups.
The group number indicates the number of electrons that exist in the outermost shell of the atoms (IA = 1 electron in its outer shell, IIA = 2 electrons in its outer shell, etc.)
The electrons in the outermost shells are called valence electrons

7. Valence electrons
These electrons are involved in chemical reactions because they are the most easily removed from the atom

8. Classification 1: Periods & Groups

9. Classification 1: Groups AKA Families
The columns on a Periodic Table are referred to as families
Remember… it’s the number of valence electrons that will determine which family (or in what group) it is
Ex. Be and Mg both have 2 valence electrons and are therefore part of the same family

10. Families IA 1 Alkali metals IIA 2 Alkaline earth metals IIIA 3
GROUP #
# VALENCE ELECTRONS
CHEMICAL FAMILY IA 1
Alkali metals
IIA 2
Alkaline earth metals
IIIA 3
Boron group
IVA 4
Carbon group VA 5
Nitrogen group
VIA 6
Oxygen group
VIIA 7
Halogens
VIIIA 8
Inert/Noble gases

12. ALKALI METALS (Hydrogen)
React violently when in contact with water (form a base/alkali)
Not found in nature as free elements
Soft, light metals that melt at low temperatures
Excellent conductors of heat & electricity

13. ALKALINE EARTH METALS Grey metallic solids (often rocks)
Excellent conductors of heat & electricity
Harder in consistency than alkali metals
Less violent reactions than alkali metals

14. HALOGENS
MOST reactive/toxic non-metal (therefore only exist as compounds)
Combine with alkali metals to form salts (halogen = “saltmaker”)
Powerful desinfectants: chlorine
Form strong acids when combined with H (ex.HCl)

15. INERT/NOBLE GASES Exceptionally stable
(= non-reactive, chemically inert)
Colourless in their natural state
Emit characteristic colours when in vacuum tubes (ex. Neon)
All gases!

16. Classification 1: Periods & Groups (2.3)
Rows on the Periodic Table are referred to as periods.
The period number indicates the number of orbits/shells an atom has.
ex. Na and Cl are both situated in the 3rd period therefore, their atoms contain 3 orbits

17. Periods = The number of shells!

18. TEST YOUR KNOWLEDGE!!! What element has
3 shells and 4 valence electrons?
4 shells and 7 valence electrons?
2 shells and 1 valence electron?
1 shell and 1 valence electron?

19. Different colours = different families

20. To summarize – organization matters!!!!
Elements (atoms) are placed in the Periodic Table in a specific way
This way depends on:
The number of valence electrons
The number of electron shells
The properties of the element
 Group
 Period
 Family

21. To come…. Elements are also placed in the Periodic Table based on
Their state (solid, liquid or gas)
Whether they are metals, nonmetals, metalloids
TO BE CONTINUED…

22. Homework  - workbook Please complete pages : p. 7 to 10
Skip questions on the simplified atomic model and neutrons!
To summarize!

23. Quiz Tuesday, period 3 Covers: workbook: 3 to 6 Book: 6 to 17
NOT NEUTRON, NOT SIMPLIFIED ATOMIC MODEL