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Periodic table

 

How are elements arranged like piano keys?

Caution analogies

The eight-note interval between any two notes on a keyboard with the same name is an octave. The sounds of musical notes that are separated by an octave are related, but they are not identical.

In a similar way, elements in the same column of the modern periodic table are related but not identical.

Picture1

{5.2 The Modern Periodic table, Prentice Hall Physical Science, Wysession, Frank and Yancopoulos}

{ Excerpted from http://www.chem4kids.com/files/elem_pertable.html }

Elements as Building Blocks

Periodic table is organized as a grid.

Each element is placed in a specific location because of its atomic structure.

The periodic table has rows (left-to-right) and columns (up-and-down).

Elements in each row and column have specific characteristics.

Color code the elemental periods

Rows read from left to right. Each row is called a period.

All of the elements in a period have the same number of atomic orbitals. We’ll learn about orbitals later.

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Color code the groups

Vertical columns are called groups.

Elements in each group have the same number of electrons in the outer orbital. (We’ll learn about orbitals later)

What do we need to know know? Some electrons are tightly bound to the atom. They stay stuck to it.

But other electrons are only loosely bound to the atom – they can easily be pulled away and shared with other atoms.

These loosely held, outer electrons are valence electrons.

Valence e- are only electrons involved in chemical bonds with other elements.

 

 

 

 

Hydrogen (H) and helium (He) on the top

Helium (He) is different from all of the other elements. It is very stable with only two electrons in its outer orbital (valence shell). Even though it only has two, it is still grouped with the noble gases that have eight electrons in their outermost orbitals. The noble gases and helium are all “happy,” because their valence shell is full.

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Additional reading

Early models of the atom
http://www.chemistryland.com/CHM151S/02-Atoms/EarlyAtom/EarlyAtom.html

The history of the periodic table
http://www.chemistryland.com/CHM151S/02-Atoms/Chaos/Chaos.htm

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Online periodic table

http://www.ptable.com/

Online PhET Chemistry labs

https://phet.colorado.edu/en/simulations/category/chemistry

Ionic bonding interactive (web app)

http://www.learner.org/interactives/periodic/groups_interactive.html

PBS web app : Ionic bonding

http://www.pbslearningmedia.org/asset/lsps07_int_ionicbonding/

Balance the charges of the polyatomic ion (web app)

http://www.chemfiles.com/flash/formulas.html

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