1. The Periodic Table

2. The Periodic Table
is a chart that organizes all the elements in a way that shows patterns – both similarities and differences among the elements.
Elements are listed by increasing atomic number.

3. The horizontal rows are called periods. There are 7 periods.
The vertical columns are called groups. There are 18 groups.
Elements in the same group have similar chemical properties.

4. Periods
Each period corresponds to the energy levels found outside an atoms nucleus
The period that an element is located in tells you what the highest energy level is that will contain electrons

5. Periods
The most energy levels found in an atom (currently) is seven which corresponds to the seven periods in the table
Example
Potassium (K) is located in period 4 and thus will have its valence electrons in the fourth energy level

6. Period 1
Period 2
Period 3
Group 1
Group 2 3 4 5 18
Period 7

7. Special Groups Group 1 elements are known as the alkali metals.
Group 2 elements are known as the alkaline earth metals.
Group 17 elements are called halogens.
Group 18 elements are called noble gases.
Groups 3-12 are called transition metals.
The Lanthanides and Actinides are the excerpts at the bottom.

8. Group 1 – Alkali Metals Have only one e- in the valence shell
Most reactive of all metals – reactivity increases as you go down the group
Hydrogen is an exception!
Has one valence electron but is classified as a non-metal

9. Group 2 – Alkaline Earth Metals
Has two e- in valence shell
Become increasingly soluble with increase in temperature

10. Group 18 – Noble Gases
Generally are chemically inert meaning they do not react with other elements
This is because they already have 8e- in their valence shell causing them to be stable
(He only has 2 valence e-)
Only He and Ne are truly inert – others will react in limited amounts under specific conditions

11. Group 17 – Halogens
Halogen means “salt former” – form salts when reacting with a metal
Most exist as diatomic molecules in gaseous state
Ex. Cl2
All are one e- short of a full valence shell causing them to be very reactive
Are non-metals

12. Transition and Rare Earth Metals
Some of the rest of the elements in the periodic table fall under these two categories
Transition metals are groups 3 – 12
Rare earth (inner transition) metals are broken down further into actinides and lanthanides

13. Transition and Rare Earth Metals
These are also called the inner transition elements and they belong here

14. Representative Elements
Groups 1, 2 (s block) and (p block) are often called representative elements. They are sometimes labelled 1A, 2A, 3A, …8A

15. These elements are called the representative elements

16. The Periodic Table

18. There are 3 major sections of elements in the periodic table:
Metals
Non-metals
Metalloids
Metals are located to the left of the “staircase line” and non-metals are to the right (except H). Metalloids border the line.

19. Properties of Metals Luster (shiny) Good conductors High density
Physical Properties
Chemical Properties:
Luster (shiny)
Good conductors
High density
High melting point
Malleable/bendable
Solid at room temperature (except Hg)
Easily lose electrons
Corrode easily (ex: rusting or tarnishing)
Low electronegativity

20. Properties of Non-metals
Physical Properties:
Dull
Poor conductor
Brittle
Not malleable
Low density and melting point
Chemical Property:
Tend to gain electrons
High electronegativity

21. Properties of Metalloids
Metalloids border the “staircase” and tend to have some properties of both metals and non-metals.
solids
can lose or gain electrons
semi-conductors of electricity (Conduct heat and electricity better than non metal but not as well as metals
Shiny or dull
Malleable

22. The Periodic Table