chapter 3 the atom
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Chapter 3 The Atom . Day One and Day Two . History of the atom notes Black Circle Activity . Black Circles . You and your partner will be given a black circle. Within the black circle is a ball and some barrier Your job is to figure out what shape the barrier is…. . - PowerPoint PPT PresentationTRANSCRIPT
Chapter 3 The Atom
HISTORY OF THE ATOM NOTESBLACK CIRCLE ACTIVITY
Day One and Day Two
Black Circles
• You and your partner will be given a black circle.
• Within the black circle is a ball and some barrier
• Your job is to figure out what shape the barrier is….
The Greek Philosophers
Democritus • Greek Philosopher
• Nature must be small particles which were indivisible
Aristotle• Greek Philosopher
• Matter was continuous
• Table (chop forever)
John Dalton
1. Matter = particles with definite size & mass
2. All atoms that make up an element have the same mass.
John Dalton
3. Atoms of 2 different elements have different masses.
4. Atoms come together in definite ratios to form compounds.
H2O
Thomson
• Studied the Cathode Ray Tubes • Rays appear on phosphorescent screen when
an electrical current is sent through • Atoms are neutral • How could the magnet affect these particles? • Must be smaller positive and negative
particles
J.J. Thomson
Rutherford
• Gold Foil Experiment
• What did he expect? – Majority of particles to hit straight across opening
What actually happened?
• Most went through
• Few particles hit foil and bounced back
Conclusions from the Gold Foil Experiment
1. Atom is mostly empty space
2. Mass is concentrated in the center
3. Nucleus is positive
RUTHERFORD MARBLE ACTIVITYDay Three
Rutherford: Measuring what you cannot see
LAB WRITE-UPREVIEW FOR QUIZ
Day Four
Dalton
1. What is the name of his theory?
2. What are elements made of?
3. An atom of hydrogen and an atom of carbon are ________
4. What are compounds made of?
J.J. Thomson
1. What did Thomson discover?
2. What is the charge of an electron?
Rutherford
1. What is the charge of an alpha particle?
2. Why is Rutherford’s experiment called the gold foil experiment?
3. How did he know the atom was mostly empty space?
Rutherford
4. What happened to the alpha particles as they hit the gold foil?
5. How did he know that the nucleus was positively charged?
LECTURE: NUCLIDE SYMBOLSQUIZ: HISTORY OF ATOMIC STRUCTURE Day Five
Structure of the Atom
• Proton – Nucleus – Positive Charged
• Neutron– Nucleus – Neutrally charged
• Electron – Outside the nucleus – Negatively charged
Nuclide Symbols
• Atomic Number
• Mass Number
Nuclide Symbol
• Write the nuclide symbol for a potassium atom that has 21 neutrons.
Lets Try a FewWrite the Nuclide Symbols
• A lithium atom with 4 neutrons
• A sulfur atom with 15 neutrons
Assignment
• Page 20 – Practice Problems: Writing Nuclide Symbols • First Four
LECTURE: NUCLIDE SYMBOLS& ISOTOPES
Day Six
Nuclide Symbols
• Mass Number
• Atomic Number
Lets Try a Few!!
• Write the nuclide symbols for the following:
– Copper- 64
– A Sulfur with has 17 neutrons
– Potassium- 39
Isotopes
• Atoms of the same number of protons but different number of neutrons
Assignment
• Page 20 and 21
Day Seven
LECTURE: NUCLIDE SYMBOLS AND IONS
Nuclide Symbols
Nuclide Symbols for Ions
• What is an ion? – An ion is a charged particle • It could be positive or negative
• What does that do to the number of protons, electrons, and neutrons?
Example
• 40K+1 , Determine the number of protons, neutrons, and electrons.
Lets Try a Few!
• Determine the number of electrons, protons, and neutrons in the following:
• 81Br-1
• 18N-3
Radioactivity
• Three types of Radioactivity – Alpha
– Beta
– Gamma
Assignment
• Page 22– Complete the first table
NUCLIDE SYMBOLS/ RADIOACTIVITY PRE-LAB FLAME TEST
Day Eight
Radioactivity
• Three types of Radioactivity – Alpha
– Beta
– Gamma
Example
Properties of Electrons
• Most of the atom’s mass is made up of ______
• Most of the atom’s volume is made up of _____
• Found in __________
Properties of Electrons
• The closer the electron is to the nucleus the less energy it has
Ground vs. Excited States
Ground State • Close to nucleus as possible
Excited State – Electrons receive energy
move farther away– Release E to drop back down
to ground state (LIGHT) – Light can be seen in different
colors – Elements can be identified by
observing the colors it releases
Assignment
• Radioactivity Worksheet
FLAME TESTREVIEW FOR NUCLIDE AND RADIOACTIVITY QUIZ
Day Nine
QUIZ: NUCLIDE AND RADIOACTIVITY LAB WRITE-UP
Day Ten
ELECTRON CONFIGURATION
Day Eleven
Locating/Mapping Electrons
• Energy Levels (n) – Higher the n farther away from the nucleus– More Energy
• Sublevels – Number of sublevels is related to the energy level – N=1 : 1 sublevel , N=2: 2 sublevels – N= 3 : ? Sublevels , N=4 : ??? , N= 5: ???
Shapes and Orbitals
• Orbital: – Most probable location of the electrons – Each orbital can hold a maximum of 2 electrons
• Shapes – 4 different orbitals that have four different shapes
– s, p, d, f
Lets try to summarize this: (Page 28)
Sublevels (Symbol)
# of orbitals
# of electrons in EACH orbital
TOTAL # of electrons possible in sublevel
s
p
d
f
ELECTRON CONFIGURATION
Day Twelve
Lets try to summarize this: (Page 28)
Sublevels (Symbol)
# of orbitals
# of electrons in EACH orbital
TOTAL # of electrons possible in sublevel
s
p
d
f
Lets dig a little deeper: (Page 28)
Energy Level(n)
# of Sublevels
Type of sublevels
# of electrons possible in each orbital
Total # of electrons possible in Energy Level
1234567
So how do we “map” out the location of the electrons?
• Aufbau Principle: – Electrons will always fill up an atom from lowest to
highest energy
• CARBON
Assignment
• Page 29 – Oxygen, Boron, Helium, Sulfur, Magnesium
ELECTRON CONFIGURATION Day Thirteen
What about the bigger elements?
• Potassium
1s2s 2p
3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f
7s 7p 7d 7f
Assignment
• Page 30 – #1-10
QUIZ: ELECTRON CONFIGURATIONMODEL OF THE ATOM
Day Fourteen
REVIEW FOR TESTMODEL OF THE ATOM
Day Fifteen
TEST Day Sixteen