Transcript Atomic Structure

CHAPTER #4 ATOMIC STRUCTURE
Objectives/Outcomes: Things you will be able to do
• Define Atom.
• List and Describe the Models of the Atom.
• Name and Describe the Parts of an Atom
• Identify the Relationships Among the Atomic #, Isotopes,
Mass #, & Average Atomic Mass of an Atom.
• Calculate the Numbers of Protons, Neutrons, & Electrons of an
Atom Given Its Symbol and Mass Number.
• Calculate the Average Atomic Mass of an Atom
Structure of an Atom
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ATOMS:
Democritus (Greek Philosopher, 4th Century BC)
‘atomos” = Indivisible
100 different naturally occurring atoms that are
called…………
Models of an Atom: A look into the past 200 years of Research
• DALTON’S MODEL: EARLY 1800’S, 4 MAIN CONCEPTS
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Models of an Atom: A look into the past 200 years of Research
• THOMSON’S MODEL: late 1800’s
• ATOMS are electrically neutral so what had to be
present to make the ATOM electrically neutral?
Models of an Atom: A look into the past 200 years of Research
• RUTHERFORD’S MODEL: 1911, FOUND (+) CHARGE
Models of an Atom: A look into the past 200 years of Research
• BOHR’S MODEL:
1913
Models of an Atom: A look into the past 200 years of Research
• ELECTRON CLOUD MODEL: NOW
ATOMIC ORBITALS AND ELECTRON CONFIGURATION
• ATOMIC ORBITALS:
• Electron Configuration:
• Stable Atom:
• Unstable Atom:
• Energy Level
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Max # of e-
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http://tw.video.yahoo.com/video/play?v
id=193831
INSIDE THE NUCLEUS
• PROTONS: (P+) Positive Charge
• In 1932 James Chadwick, a former student of
Rutherford, stated that the Nucleus is more complicated
than previously thought. He discovered………
• Q: How are p+ and n packed together so tightly?
• A:
• ATOMIC NUMBER:
Atomic #
• Examples:
– Sodium (Na)
– Iron (Fe)
• Q: How many electrons does each Element have?
• A: #
– Sodium (Na)
– Iron (Fe)
HOW MANY NEUTRONS DOES EACH ELEMENT HAVE?
• The # of Neutrons can be….
MASS NUMBER / ATOMIC MASS
• MASS #:
• Q: What is the difference between C-12 and C-14?
• Q: What units do we place by these Mass #’s?
Average Atomic Mass: Sum of the masses of all the Elements Isotopes