Transcript GO 3_3 The Periodic Table

GO 3
Describe ideas used in interpreting the chemical nature of matter,
both in the past and present, and identify example evidence that
has contributed to the development of these ideas
3-3 The Periodic Table
Guided Question
What is the periodic table of
elements? And how is it organized?
Mendeleev
A picture of Mendeleev’s Original
Periodic table and the scientist
himself!
1869 – Dmitri
Mendeleev
Organized the 63 known elements into a series of rows and
columns based on physical and chemical properties
He left gaps in the table explaining there were elements
that had not been discovered yet
He then hypothesized about the physical and chemical
properties of the atoms that would fill the voids
After his table was published, gallium was discovered and
with properties almost exactly the same as Mendeleev
predicted, it fit in an open space!
Breaking Down the
Element
Breaking Down the Element
Indicates number of Protons in the
nucleus & number of electrons orbiting
Understanding the Periodic Table
Need to know:
Metals are
Yellow
Non-metals
are green
Metalliods are
purple
Metals vs. Non-metals
___
OR
vs
Metals
Grouped on the Right side of the periodic table
(88 of the elements are metals)
Physical Properties:
Shiny solids at room temperature
High conductors of heat and electricity
Ductile (can be formed into wires)
Malleable (rolled and can be beaten into thin sheets)
Non-metals
Grouped on the right side of the periodic table
Physical Properties:
May be solid, liquid or gas at RT
Poor conductors of heat and electricity (called
Insulators)
Solid forms are dull and brittle
Metalloids
have both metallic and non-metallic properties
Tellurium
Silicon
Understanding the Periodic Table
Each horizontal version is called a PERIOD (1 to 7)
Each Vertical column forms a group (or FAMILY) (1-18)
Understanding the Periodic Table
Need to know:
Group 1
Group 2
Group 17
Group 18
____ Metals – Group 1
Alkali Metals – Group 1
The most reactive of the metals
They react when exposed to air or water
As you move down the group, reactivity increases.
Lithium
Cesium
Sodium
Alkaline Earth Metals –
Group 2
Alkaline Earth Metals
– Group 2
They react when exposed to air or water but not as
strong as that of the alkali metals
Halogens– Group 17
Halogens– Group 17
The most reactive non-metals (Fluorine can etch glass)
Can combine with other elements to form new substances; Ex: Na +F
= sodium fluoride found in Toothpaste
Various colors and physical states
F and Cl = yellowish green gas;
Br = dark red liquid;
I = purple-black solid with a metallic crystalline sheen
Inert Gases – Group 18
Inert Gases – Group 18
Also known as the NOBEL GASES
The most Stable and unreactive elements; long
thought that they could not combine with other
elements
1962 – Canadian Chemistry Neil Bartlett (B.C.) was the
first to prepare a compound containing a noble gas
(XeF4)
What is the deal with
Hydrogen
Considered to be a Non metal element (Sometimes has a special
or separate spot on some versions of the Periodic Table)
Here are basic facts about the Hydrogen element in the periodic
table:
Is the most abundant element in the universe (75% of
everything is H)
Hydrogen gas is extremely flammable (The Hindenburg)
Is a colourless and odourless gas at room temp
Can take on a negative charge (H-) or a positive charge (H+)
Hydrogen is the lightest of all elements - atomic mass 1.00794