Isotopes

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Isotopes
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Isotopes Are.

• Atoms w/ same of p but different no
• ?different mass s
• chemically alike- react the same way
• b/c identical of p e-
• Atomic Mass rounds to most abundant isotope

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Atomic Mass Formula
( Mass Abundance) (Mass Abundance)
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Example 1

• Mass (amu) x Abundance () Relative Mass
• 35Cl 34.97 x 75.78
  26.50 amu
• 100
  
• 37Cl 36.97 x 24.22
  8.954 amu
• 100
• Atomic mass of Cl
  35.45 amu

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Example 2

• Two isotopes of gallium are naturally occurring
  with 69Ga at 60.11 (68.93 amu) and 71Ga at
  39.89 ( 70.92 amu). What is the atomic mass of
  gallium?