REVIEW Parts of an Atom

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REVIEW Parts of an Atom

• The Atom has THREE basic subatomic particles
• PROTONS ( charge)
• NEUTRONS (o charge)
• ELECTRONS (- charge)

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REVIEW Parts of an Atom

• PROTONS and NEUTRONS are in the NUCLEUS.
• ELECTRONS are in charged electron clouds or
  shells surrounding the nucleus.

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Bohr Model
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Quantum Model
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Counting PROTONS

• To find the number of PROTONS, look at the ATOMIC
  NUMBER on the PERIODIC TABLE.

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Counting ELECTRONS

• ELEMENTS are NEUTRAL.
• This means in elements, the number of ELECTRONS
  is EQUAL TO the number of PROTONS.
• electrons protons
• The element Carbon has 6 protons so it also has
  6 electrons

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Its different for IONS!

• By definition, an ION is an atom that has lost or
  gained electrons.
• An atom that LOSES an electron becomes POSITIVELY
  charged and is called a CATION.
• An atom that GAINS an electron becomes NEGATIVELY
  charged and is called an ANION.

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Ions - Flashcard Alert!

• The number of ELECTRONS in an ION will be GREATER
  or LESS than the number of PROTONS.
• In IONS, electrons ?? protons!

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Example Sodium Ion

• Sodium gives up one electron to form a Sodium
  ION (1) charge

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Counting NEUTRONS

• Each ISOTOPE of an element has a different
  number of NEUTRONS.
• To find the number of neutrons in a specific
  isotope, just subtract the number of protons from
  the atomic mass NUMBER (not the atomic mass in
  the Periodic Table!)

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Carbon Isotopes
Carbon-126 protons 6 neutrons
Carbon-146 protons 8 neutrons
Carbon-136 protons 7 neutrons
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Or Look At It This Way

• Isotopes of Carbon