Atomic Structure and the Periodic Table

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Atomic Structure and the Periodic Table
Chapter 5

• Chapter 5

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• The Structure of the Atom
• A. Three particles make up the structure of
  atoms
• 1) protons . positive charge ()
• 2) neutrons no charge (neutral)
• 3) electrons negative charge (-)

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• B. These particles are located in one of two
  locations
• 1) in the nucleus protons and neutrons
• 2) around the nucleus - electrons

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• C. The mass of an atom is concentrated in the
  nucleus

Atomic mass sum of protons neutrons
D. The Periodic Table indicates the number of
protons in each element
Atomic number number of protons
The atomic number identifies the element
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• E. Shorthand notation is used to indicate the
  element, atomic number and atomic mass

Carbon 6 protons 6 neutrons
Sodium 11 proton 12 neutrons
Hydrogen 1 proton 0 neutrons
Hydrogen-1
Carbon-12
Sodium-23
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• Practice Indicate the name, number of protons
  and number of neutrons

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• Isotopes
• A. Atoms of the same element that have
  different atomic masses because they have
  different numbers of neutrons

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• B. The atomic number identifies the element
• C. The atomic mass sum of protons neutrons
• D. Only neutrons can change the atomic mass

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• Examples

Neon 10 proton 10 neutrons
Neon 10 proton 12 neutrons
Neon 10 proton 11 neutrons
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90.48
0.27
9.25
What would be the atomic mass of neon?
20 x .9048 18.10 21 x 0.0027 0.06 22 x 0.0925
2.04 20.20
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• III. Electrons
• A. A NEUTRAL atom has the same number of
  electrons as protons
• B. ION an atom that has a charge because it
  has lost or gained electrons

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• IV. The Periodic Table
• A. The periodic table is arranged in specific
  rows and columns according to their chemical
  behavior
• B. Specific regions have been named

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