MCQ Detailed View

The nanometer (nm) is a unit of length used to measure extremely small distances, particularly at the atomic and molecular scale. It is a submultiple of the meter, which is the standard SI unit of length. 1 nanometer = 10⁻⁹ meter, meaning that one nanometer is one-billionth of a meter.

To understand this better, consider that:

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  1 meter = 1,000 millimeters (10³ mm)

  
  


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  1 millimeter = 1,000 micrometers (10⁻³ m)

  
  


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  1 micrometer = 1,000 nanometers (10⁻⁶ m)

  
  

Thus, 1 nanometer = 0.000000001 meter (10⁻⁹ m). This unit is mainly used in physics, chemistry, biology, and nanotechnology to describe the size of particles, molecules, wavelengths of light, and other microscopic phenomena.

For example:

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  A DNA double helix is about 2 nanometers wide.

  
  


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  The wavelength of visible light ranges from approximately 400 to 700 nanometers.

  
  


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  Many semiconductor devices are designed at the nanometer scale in modern electronics.

  
  

The nanometer is crucial because it allows scientists to describe and work with things that are too small to be seen with the naked eye. Advanced microscopes, like electron microscopes, can detect objects at the nanometer scale, which is essential in studying materials, viruses, and nanosized machines.

The other options in this question are incorrect:

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  10⁻³ meter = 1 millimeter (too large)

  
  


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  10⁻⁶ meter = 1 micrometer (larger than nanometer)

  
  


• 
  

  10⁻¹² meter = 1 picometer (smaller than nanometer)

  
  

Hence, 1 nanometer equals 10⁻⁹ meters, making option C the correct answer. This unit highlights how precise and detailed measurements in science can be when studying objects at the smallest scales of matter.