1. A2.1
The Periodic Table

2. Based on their properties… elements can be divided into 3 classes
The Elements:
There are about 90 naturally occurring elements, and another 25 synthetic elements.
Based on their properties… elements can be divided into 3 classes
Metals
Metalloids
Non-Metals

3. METALS Highly reactive with other substances.
Most of the elements are metals
METALS
Most are solids at room temp
Most are silver/grey in colour and shiny
All good conductors of heat and electricity
Are malleable (shapeable) and ductile (can be stretched)

4. NON-METALS Exist as solids, liquids or gases at room temperature
Only 17 elements are non-metals
NON-METALS
Grouped together because they lack resemblance to metals…not because they are similar to each other
Lots of variation in colour

5. They are considered the intermediate between the two ends of the Periodic Table
All the remaining elements
METALLOIDS
They have properties that fit with BOTH metals AND non-metals
Some conduct electricity, but not very well, or under specific conditions (called semiconductors)

7. Group IA: Alkali Metals Group IIA: Alkaline Earths
Group VIIA: Halogens
Group VIIIA: Noble Gases
Metals:
Nonmetals:
Lanthanide Series: AKA rare earths
Actinide Series: AKA transuraniums

8. Notice METALS are on the LEFT SIDE and CENTRE of the table.
The Periodic Table
The periodic table organizes ALL the elements according to their chemical properties.
Notice METALS are on the LEFT SIDE and CENTRE of the table.
The NON-METALS are on the FAR-RIGHT (With one exception – HYDROGEN – which is located on the left side since it often behaves like a metal in chemical reactions)
The METALLOIDS are between them, located right along the STAIRCASE LINE.

9. A Closer Look at your Table
Atomic Number
Chemical Symbol
Chemical Name
Atomic Mass
Charge in Compound
Name in Compound

10. Organization: The periodic table is organized into rows and columns.
Each horizontal line (or row) is called a period.
Represents electron arrangement. 1 2 3 4 5 6 7

11. Organization:
Each vertical column forms a group (or family) of elements numbered 1 to 18.
The chemical families are groups of elements that have similar chemical and physical properties. 1 18

12. Families Sodium GROUP 1 – ALKALI METALS
- They are soft, shiny and silver in colour
- They are the most reactive elements
- Francium is the most reactive metal Fr

13. Families Magnesium GROUP 2 – ALKALINE EARTH METALS
- They are shiny and silver in colour, but not soft
- They are the second most reactive group
- Called “Alkaline" earth metals because they form "alkaline" solutions (OH) when they react with water, so they have a pH greater than seven and are basic.

14. Families Fluorine GROUP 17 – HALOGENS
- These elements are poisonous and react readily
- Colored non-metallic elements, colour gets
deeper as you move down the group
- Fluorine is the most reactive non-metal F

15. Families Neon GROUP 18 – (INERT) NOBEL GASES
- These elements are very unreactive

16. Lastly... The Staircase separates the metals from the non-metals

17. Atomic Theory Subatomic Particles
An atom is the smallest part of an element that still has the properties of that element
Subatomic Particles
PROTONS (+)
ELECTRONS ( - )
NEUTRONS (no charge)

18. The Atom has the same # of protons and electrons.
Proton/Neutron/Electron Numbers
The Atom has the same # of protons and electrons.
Atomic Number = number of protons and electrons.
Number of Neutrons = Atomic Mass – Atomic number
Atomic Number
p+ = 35
p+ and e–
e– = 35
no =
79.90 – 35 = 44.90
Atomic Mass
Round: no = 45
no = Atomic Mass – Atomic Number

19. Isotopes
are Atoms from the same element that contain different numbers of neutrons.
Notice in the last example…the no = 44.90
This means that Bromine usually has 45 neutrons , however it can sometimes exist as an isotope with 44 neutrons
                         
                
                            
The atomic symbol is sometimes show with the mass number and the atomic number
Using this format, the isotopes for Bromine are:
and

20. More Isotopes Isotopes have the same number of protons
but different numbers of neutrons
Example: Isotopes of Hydrogen
Hydrogen Hydrogen Hydrogen
(99% of natural (deuterium) (tritium)
hydrogen is this found in "Heavy"
isotope) water

21. Examples: 1. Aluminum p+ = 13 e– = 13 no = 26.98 - 13 no = 13.98
Atomic Number = 13
e– = 13
Atomic Mass =
26.98
no =
no =
Note: As an isotope, Aluminum most often exits with 14 neutrons, but sometimes has 13!
Round = no = 14
2. Lead

22. Energy Levels
Electrons (-) take up most of the volume of an atom (like 99.9% of it!) and they occupy specific energy levels.
An energy level is a space near the nucleus that may be empty OR may contain electrons.
Electrons in energy levels near the nucleus have the lowest energy.
Energy Levels
e -
Electrons that are farther away from the nucleus have the more energy.
Nucleus

23. Orbits or Energy Levels
Energy Levels of Electrons
Valence electrons – the electrons in the outermost energy level
* Maximum number of electrons held by each energy level
the rest
18e-
18e-
8e-
8e-
2e-
Orbits or Energy Levels
Energy levels can be empty, partly filled or completely filled!
Nucleus

24. Noble Gases...

25. SOLUTION!
Metals and non-metals can find a mutual solution to their electron's problem!

27. The Octet Rule:
The Rule of Eight states that atoms bond in such a way as to have eight electrons in their valence energy levels.
This is another way to say that atoms tend to be stable with full outer energy levels.
How many electrons do we need to gain or loose to stay stable???
fluorine
neon
magnesium

28. Homework:
Read pages 28 – 39
A2.1 Check and Reflect
page 39 #’s 1 – 13