Transcript Bohr`s Theory of the Atom

Bohr Model
Starter:
What do you picture when you
think of an atom?
(What does it look like?)
Practice:
Bohr’s Model of the Atom
How to draw the model
Bohr’s Atomic Theory
The Bohr model was a modification of the
Rutherford model.
Bohr however put the electrons in certain
circular orbits around the nucleus called
shells.
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Bohr’s Atomic Theory
Protons and neutrons are found in the nucleus.
Electrons orbit the nucleus in various shells.
Everything else is empty space.
1st shell
Nucleus
0
Empty
space
2nd shell
+
3rd shell
Bohr’s Atomic Theory
Each of the shells has a maximum number of
electrons that it can hold.
1st shell
2 electrons
Nucleus
Empty
space
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2nd shell
8 electrons
3rd shell
18 electrons
Bohr’s Atomic Theory
Ex.1) Draw a Bohr model of Hydrogen-1.
Step-1 Draw a circle to represent the nucleus.
Step-2 Determine the number of protons and
neutrons and place them in the nucleus.
Step-3 Draw a circle around the nucleus to
represent the electron shell.
Step-4 Place the electron in the shell.
1p
0n
H-1
e-
Bohr’s Atomic Theory
Ex.2) Draw a Bohr model of Helium-2.
Step-1 Draw a circle to represent the nucleus.
Step-2 Determine the number of protons and
neutrons and place them in the nucleus.
Step-3 Draw a circle around the nucleus to
represent the electron shell.
Step-4 Place the electron in the shell.
e-
Helium-2
2p
2n
e-
Bohr’s Atomic Theory
Ex.3) Draw a Bohr model of Lithium-3.
Step-1 Draw a circle to represent the nucleus.
Step-2 Determine the number of protons and
neutrons and place them in the nucleus.
Step-3 Draw circles around the nucleus to
represent the electron shells.
Step-4 Place the electrons in the shells.
e-
Litium-3
3p
4n
e- e-
Bohr’s Atomic Theory
Ex.4) Draw a Bohr model of Neon-10.
Step-1 Draw a circle to represent the nucleus.
Step-2 Determine the number of protons and
neutrons and place them in the nucleus.
Step-3 Draw circles around the nucleus to
represent the electron shells.
Step-4 Place the electrons
in the shells.
e- eee-
Neon-10
e-
10p
10n
e- e-
e- e
e-
Application
Using the Atom Game board you will build the following atoms:
Sodium
Neon
Boron
Aluminum
Write the elements Name, Atomic #,
Protons, Electrons and Neutrons in you
journal BEFORE using the game
board.
Connection
How did “building” your atoms
help you understand Bohr’s
model?
Exit
What are the limitations of Bohr’s
model?