Which of the following value is the atomic mass of nitrogen ?

  1. 14 µ
  2. 16 µ
  3. 24 µ
  4. 28 µ

Answer (Detailed Solution Below)

Option 1 : 14 µ
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Detailed Solution

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The correct answer is 14 µ.    

Key Points

  • The atomic mass of nitrogen is 14 µ. 
  • Atom: 
    • An atom is the smallest invisible unit of matter that constitutes a chemical element.
    • Every plasma, solid, gas & liquid, composed of ionized or neutral atoms.
    • Around 100 picometers across, atoms are extremely small. 
  • Atomic Mass: 
    • The Atomic Theory of Dalton suggested that each element has a unique atomic mass.
    • The law of constant proportions could be explained easily by the implementation of Dalton's theory.
    • As the size of an atom is relatively small, it is quite difficult to determine the mass of an atom.
    • That's why the scientists started evaluating the mass of an atom by differentiating it with the mass of a standard atom.
    • The atomic mass is 12u (12 atomic mass units).
    • Thus it states that 1 atomic mass unit = Mass of 1/12 the mass of a carbon-12 atom.
  • The following table shows the list of elements with the respective atomic masses
    Elements Atomic Mass
    Hydrogen 1 µ
    Carbon 12 µ
    Nitrogen 14 µ
    Oxygen 16 µ
    Magnesium 24 µ
    Sodium 23 µ
    Calcium 40 µ
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