Transcript Slide 1

The Periodic Table of the Elements
Connecting the Atom to Elements
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The different types of atoms make up the 100
different elements that are known to man.
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What are those 100 elements?
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The element song: Tom Lehrer
Inside the Squares on the Table
Look at the Periodic Table on pg. 80-81. Shows
all elements in the entire world!
Dmitri Mendeleev
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In the 1800s, scientists began to
believe the elements could be
organized in a useful way
A scientist named Mendeleev
began observing the elements
and noticed that some elements
shared similar characteristics
Began organizing all of the
elements
The Periodic Table
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Mendeleev created the first Periodic Table in
1869
Periodic means “a regular repeated pattern”
The properties of the elements repeat
themselves in how they are arranged on the
periodic table
Patterns in the Periodic Table
How the table is organized:
Look at the periodic table.
Talk with your partner.
What patterns do you notice about how it is
arranged?
Write them down!!
Patterns in the Periodic Table
1. atomic mass
(the mass of one atom of the element)
Hydrogen has smallest atomic mass
Mendeleev began to notice more patterns when
he arranged the elements by their atomic mass
Patterns in the Periodic Table
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Today, the periodic table is arranged by atomic
number
Atomic number- the number of protons in the
nucleus
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Every element has a different number of protons in its
nucleus!!!
Patterns in the Periodic Table
Arranged into columns and rows
The columns are called groups (or families)
- the groups have similar characteristics
The rows are called periods
- the elements will gradually change
properties as you move across the rows
One More Pattern
Remember the atom??? Remember the parts of
the atom???
The electrons determine whether or not a
element with bond (or connect) to other types of
elements
The electrons are at different distances from the
nucleus
continued...
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The electrons that are furthest away can be
shared or transferred to other atoms
Valence electrons- electrons that are involved in
transfer or sharing
Elements have different numbers of valence
electrons. These electrons will increase from
left to right across a period
The Periodic Table