1. Trends on the Periodic Table
More than just a table!

2. The First Periodic Table
Dimitri Mendeleev was one of the first to publish a table using these properties to arrange the elements.
He placed similar elements in the same vertical column.
He left open spaces on his chart for elements he predicted would someday be found but had not been discovered at that time.

3. The Periodic Law
 He developed the idea of the Periodic Law: “When elements are arranged in order of increasing atomic weight their properties are repeated periodically.”
Today we know that atomic number is a better way to structure the periodic table. Mendeleev and other early researchers did not know about protons and neutrons and isotopes.

4. FAMILIES on the Table
Families (a.k.a. Groups)- a vertical column on the periodic table in which elements have similar chemical reactivity

5. Group 1 – Alkali metals Include Li+, Na+, K+, etc.
most chemically reactive of the metals (must be stored under oil as they will react with air)
react explosively with water
are so soft they can be cut with a knife
YOU’VE GOT TO SEE THIS!
YOU TUBE CLIP: K + H2O

6. Group 2 – Alkaline Earth metals
Includes Be+2, Ca+2, Mg+2, etc.
are very chemically reactive and are never found free in nature (same as alkali metals)
React with water to produce alkaline (i.e. basic) solutions

7. Group 17 – Halogen family F- , Cl- , Br-
named from “salt former”, these elements exhibit all 3 physical states at room temp!
are highly reactive with metals, especially alkali metals (as a result they are highly toxic)

8. Group 18 - Noble gases Include He, Ne, Xe, etc
are all EXTREMELY STABLE and only rarely react to form compounds
Sometimes called INERT GASES
all are gases which are naturally occurring
when given energy (with electricity or extreme heat) each noble gas gives off a unique colour…

9. PERIODS on the Table Periods- a horizontal row on the periodic table
Sodium (Na)
Family Name: Alkali metals
Family #: 1
Group #: 3

10. Organization of the Periodic Table
The periodic table organizes all known elements.
Elements are listed in order by atomic number
Metals are on the left (the transition metals range from group 3 to group 12), non-metals are on the right, and the metalloids form a “staircase” in the middle.
Rows of elements (across) are called periods.
All elements in a period have their electrons in the same general area around their nucleus
Columns of elements are called groups, or families
All elements in a family have similar properties, and bond with other elements in similar ways
(c) McGraw Hill Ryerson 2007
See page 171

11. Group 2 = alkaline earth metals Group 17 = the halogens
Group 1 = alkali metals
Very reactive metals/unstable
Group 2 = alkaline earth metals
Somewhat reactive metals
Group 17 = the halogens
Very reactive non-metals/ unstable
Group 18 = noble gases
Gases, Not reactive at all, Very stable because they have a full outer shell of electrons

12. (c) McGraw Hill Ryerson 2007
See page 172
(c) McGraw Hill Ryerson 2007