Get to know wavelength sizes! Use the tool at the bottom of the page to answer to these questions:

The length of this C₂H₆ Molecule , composed of 2 carbon atoms and 6 hydrogen atoms, is about 50 angstroms
(Image courtesy Scott Van Bramer at Widener University)

What types of light have a wavelength shorter than the length of a C₂H₆ molecule?

This is an electron microscope image, or micrograph, of a strand of DNA.  The DNA has been tagged with tiny particles of gold, which show up as the dense black dots.  Each dot is about 120 angstroms in diameter, while the whole strand is about 3000 angstroms across.

What type of light has a wavelength of 100 angstroms?  What about 3000 angstroms?

The length of a red blood cell is about 80,000 (eighty thousand) angstroms

What kind of light has a wavelength of eighty thousand angstroms?

The single-celled animal in this electron micrograph, is 5,000,000 (five million) angstroms wide.

What type of light has this wavelength?

The length of the body of this fly is about 60,000,000 (sixty million) angstroms 

What type of light has a wavelength as long as the body of a fly?

The length of the wingspan of this butterfly is about 500,000,000 (five hundred million) angstroms

Are there types of light that have wavelengths this long?  Yes! There is no limit to the wavelengths of radiation.

Hmmm. 34 quadrillion angstroms! maybe the angstrom is not the best unit for measuring for all types of light. Angstroms work well for short wavelengths, such as ultraviolet or visible, but once we start talking about longer wavelengths of light, other units of measurement are more appropriate. What units would you use for measuring the wavelength of infrared, microwave, and radio light waves?

Which of the objects above was closest in length to the wavelength of visible light?