periodic table. why is it organized the way that it is? individual atoms do not have physical and...
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Periodic Table
Why is it organized the way that it is?
Individual atoms do not have physical and chemical properties that we could recognize in ways that we are familiar with
Elements however do, and when we talk about properties of the periodic table this is what we are talking about
Elements are arranged in the periodic table based on these properties (the way they act)
Periods (rows)
When you look at a periodic table, each of the rows is considered to be a different period
In the periodic table, elements have something in common if they are in the same row.
All of the elements in a period have the same number of atomic orbitals. (number of electron shells)
Groups
When a column goes from top to bottom, it's called a group.
The elements in a group have the same number of electrons in their outer orbital
Example: Every element in the first column (group one) has one electron in its outer shell. Every element on the second column (group two) has two electrons in the outer shell
There are exceptions, but you don’t need to worry about that now
The white are transition metals, and they are not in a group
Group Names
The groups (columns in the periodic table) are numbered 1-18.
Some groups enjoy non-systematic names as well. Group 1 (alkali metals) Group 2 (alkaline earth metals) Group 17 (halogens) Group 18 (noble gases)
Families
The families of elements are determined by their chemical properties
Each family reacts a different way with the outside world
Usually, the columns of the periodic table are used to define families (but not always)
Families (con’t)
The Periodic table can be divided into nine families of elements each having similar properties:
Color the periodic table in your lab notebook and create a key using the following website: http://www.chemicool.com/ Alkali Earth Alkaline Earth Transition Metals Other Metals Metalloids Non-Metals Halogens Noble Gases Rare Earth
Alkali Earth Metals
Found in group 1 of the periodic table Highly reactive metals that do not occur freely in
nature. Have only one electron in their outer shell.
Therefore, they are ready to lose that one electron in ionic bonding with other elements.
Malleable, ductile, and are good conductors of heat and electricity
The alkali metals are softer than most other metals.
Alkaline Earth Metals
Found in the second group of the periodic table
All alkaline earth elements are very reactive (they will interact a lot with other elements)
Transition Metals
The 38 elements in groups 3 through 12 of the periodic table are called "transition metals."
Both ductile and malleable, and conduct electricity and heat
Rare Earth
All of the rare earth metals are found in group 3 of the periodic table, and the 6th and 7th periods
Many of these elements are synthetic, that is, human-made
Other Metals
The "other metals" elements are located in groups 13, 14, and 15
Ductile and malleable All of these elements are solid, have a
relatively high density, and are opaque
Metalloids
Metalloids are the elements found between the boundary that distinguishes metals from non-metals
Metalloids have properties of both metals and non-metals.
Some of the metalloids, such as silicon and germanium, are semi-conductors.
Non-Metals
Non-metals are the elements in groups 14-16 of the periodic table.
Non-metals are not able to conduct electricity or heat very well.
Non-metallic elements are very brittle. The non-metals can be gases, such as
oxygen and solids, such as carbon. The non-metals have no metallic luster, and
do not reflect light.
Halogens
The halogens are five non-metallic elements found in group 17 of the periodic table
All halogens have 7 electrons in their outer shells
Noble Gases
The noble gases are found in group 18 of the periodic table.
These elements have full valence shells and so are stable and not likely to react with other elements.