Download PS.3 The Atom Model

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Nine Weeks is here!
1
If you refuse to learn,
no one can help you.
If you are determined to learn,
no one can stop you!
PS.3 The Atom Model
The student will investigate and understand
the modern and historical models of the
atomic structure.
Parts of an Atom
• Subatomic particles
– 3 types
1.
2.
Protons
– Positively charged ( + )
– Set amount for each element
» Equals the atomic number
Neutrons
– No charge = neutral ( 0 )
– Close to the size of protons
– Protons and neutrons are made up of quarks
3.
Electrons
– Negatively charged ( - )
– Smallest subatomic particle
PS.3 Atomic Model: The student will understand the historical & modern model of the atomic structure
Locations within the Atom
• Nucleus
– Central part of an atom
– Where majority of mass is located
– Contains protons & neutrons
– Mass number or atomic mass number
• Electron cloud
– Orbitals or shells
• Where electrons are located constantly moving
PS.3 Atomic Model: The student will understand the historical & modern model of the atomic structure
Electron Cloud
• Made up of energy levels
– Also called shells or orbitals
• Each energy level can hold a limited number of electrons
– Electrons on the outermost shell are called valence electrons
• Octet Rule- Atoms will gain or lose electrons to have 8
electrons in their outermost shell
• 8 electrons = full shell = stability
Electron Cloud
4th Shell – 32 electrons
3rd Shell – 18 electrons
2nd Shell- 8 electrons
1st Shell – 2 electrons
Nucleus
Parts of an Atom
Energy Levels
Shells
Orbitals
Cloud
Protons and
neutrons make up
the nucleus
Parts of an Atom
Atomic mass
Atomic number = Number of Protons
Atomic Mass = Number of Protons + Number of Neutrons
Charges of an Atom
• Charges in the nucleus:
• 6 protons (+)
• 6 neutrons (0)
• Overall charge = positive
• Overall charge of the whole atom:
• 6 protons (+)
• 6 neutrons (0)
• 6 electrons (-)
• Overall charge = neutral
Model
• 5 Historical Models
– Dalton
– Thomson
– Rutherford
– Bohr
– Electron-Cloud
Democritus & Dalton
• Democritus
– ~ 400 B.C.
– Greek philosopher
– Said all matter is made up of small particles
• Named particles Atomos
– Un-cuttable
– He was unable to prove his idea
• John Dalton found proof in 1800’s
– Solid sphere
PS.3 Atomic Model: The student will understand the historical & modern model of the atomic
structure
Thomson
• 1904
– Positive sphere with negative parts
embedded (spread all over)
– Chocolate chip cookie model
• Chips = electrons
• Cookie = 1 big proton
proton
PS.3 Atomic Model: The student will understand the historical & modern model of the atomic
structure
Rutherford Model
• 1911
– Solid positive nucleus w/ majority of mass
surrounded by electrons
PS.3 Atomic Model: The student will understand the historical & modern model of the atomic
structure
Bohr Model
• 1913
• Electrons in fixed orbits around nucleus
• Nucleus made of positive protons &
neutral neutrons
PS.3 Atomic Model: The student will understand the historical & modern model of the atomic
structure
Electron Cloud
• Current Model
– Developed in 1926
– Nucleus made up of protons & neutrons
– Electrons are not in fixed orbits
• Are frequently in certain areas
PS.3 Atomic Model: The student will understand the historical & modern model of the atomic structure
Schrödinger and Heisenburg
• Developed the Electron Cloud Model
• Came up with a mathematical equation
– Predicted which electrons are likely to be found
– Cannot determine where an electron is at any given
moment
BrainPop
• Atomic Model
Snapshot
1.
2.
3.
4.
5.
The majority of the mass of an atom in located
in the ____________.
Protons and neutrons are made up of
__________.
The overall charge of an atom with equal
numbers of subatomic particles is ___________.
The charge of the nucleus is _______.
Electrons have a ___________ charge.
Snapshot
1. What is the atomic number
of this atom?
2. What is the atomic mass of
this atom?
3. How many valence
electrons does this atom
have?
4. What atom is this? (Hint:
Look at the periodic table in
your agenda)
Model an Atom
• Use the periodic table to pick an atom
from the first three rows
Model an Atom
• What’s the atomic number?
• How may protons, neutrons, and electrons
does your atom have?
Model an Atom
Record that data here
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Model an Atom
Create your nucleus
in the center of your page
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Model an Atom
Draw the first energy level
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Model an Atom
How many electron fit on this level?
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Model an Atom
Two electrons on the first level
Do you have any more electrons?
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Model an Atom
Draw the second energy level
How many electrons fit on the second level?
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Model an Atom
Up to 8 electrons on the second level
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Model an Atom
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Some of you
may need a
third level
Model an Atom
Carbon
P (+) = 6
N (o) = 6
E (-) = 6
Up to 18
electrons on
the third level
Electron Arrangement
• Each energy level hold a limited number
of electrons
– There is a maximum number that can fit on
each shell
Electron Arrangement
Bohr Models
• Use the periodic table to identify how
many particles are in each atom
• Draw a Bohr diagram of each atom