The Periodic Table
of Elements
Henry Moseley (1887-1915)
• Made improvements to
Mendeleev’s Periodic
Table
• Arranged elements by
atomic number instead
of mass
• Realized that there were
undiscovered elements
The periodic table holds all the
• chemical elements found on
Earth.
Describe the Periodic Table
• Elements are arranged left to right
and top to bottom in order of
increasing atomic number.
Introducing: The Atom
• https://www.youtube.com/watch?v=hhbqIJZ8wCM
• Elements have different atomic numbers - the
number of protons or electrons increases up the
table as electrons fill the shells.
Describe the Periodic Table
. The number of protons plus neutrons in the nucleus of the
atom is the atomic mass.
Each element has a different atomic mass. This number
increases as you go across the rows from top to bottom
of the table.
I will be able to describe what an Element is
and how to use the Periodic Table.
What is the Periodic Table?
• Periodic Table
Element Name
Atomic #
•Indicates the
number of
Protons.
Atomic Mass
•The weighted
Average of the
masses of the
naturally occurring
isotopes.
Chemical Symbo
•1-2 letter
abbreviation
•1st letter capitalized
•2nd always
lowercase
I will be able to use the info displayed on the periodic
table to determine characteristics of the elements.
What is The Periodic Table?
• Periodic Table
Atomic
number
Atomic Mass
(round this number)
Number of Protons = Atomic Number
Number of Neutrons = Atomic Mass - Atomic
Number
Number of Electrons = Atomic Number
I will be able to use the info displayed on the periodic
table to determine characteristics of the elements.
Write down the number of Proton, Neutron
and Electron of Hydrogen?
• Periodic Table
I will be able to use the info displayed on the periodic
table to determine characteristics of the elements.
Write down the Number of Proton, neutron
and Electron.
• Periodic Table
I will be able to use the info displayed on the periodic
table to determine characteristics of the elements.
Write down the Number of Proton, neutron
and Electron.
• Periodic Table
•Energy Levels
The energy that an
electron has is based on
where it is around the
nucleus. (Electrons that
are closer to the
nucleus have less energy
than those that are
farther away from the
nucleus)
Energy Levels
•
•
•
•
Level
Level
Level
Level
1-2 electrons
2-8 electrons
3-8 electrons
4-18 electrons
Each level must be full before
another can be started.
EXAMPLE
It would look like this..
So let’s try it….
• How to draw a Lithium atom
• First, look at the Periodic Table
• Second, determine the number of
protons (Look @ the atomic number)
• Then determine the number of
neutrons (Atomic mass – atomic
number)
• Then determine the number of
electrons (Look @ the atomic number)
3
Li
Lithium
7
Created by G.Baker
www.thesciencequeen.net
So let’s try it…. Protons = 3
3
-
Li
+
+
+
-
Lithium
-
7
Electrons = 3
2 in the 1st shell, 1 in the 2nd shell
Neutrons = 4
(7-3=4)
Created by G.Baker
www.thesciencequeen.net