Mood rings were invented in 1975 by Joshua Reynolds and contain thermochromic liquid crystals that change color based on temperature. The crystals absorb heat and refract light at different wavelengths - shorter wavelengths appear more blue while longer wavelengths appear more red. When the body is warm, the crystals refract shorter wavelengths and the ring appears blue/purple. When the body is cooler, the crystals refract longer wavelengths and the ring appears more red. The ring acts like a thermometer to indicate changes in temperature through color changes.

1. THE CHEMISTRY OF
MOOD RINGS
By: Kennedy Murphy

2. BASIC INFO.
• Invented by Joshua Reynolds in 1975
• Think of a thermometer
• Ring is filled with thermochromic liquid crystals (“How the Chemistry” 1)

3. CHEMISTRY
• When temperature changes, reactions occur!!
• crystal structures absorb heat and refract it at different wavelengths (“How
the Chemistry” 1)
• What is a wavelength?...

4. MORE CHEM.
• Electromagnetic Spectrum
(Buthelezie 139)
If wavelength is short, the
molecules refract a more blue
color
If the wavelength is longer, the
molecules refract more of a red
color

5. CHEMISTRY
• Hot objects have shorter wavelengths while cooler
objects have longer wavelengths(“How the Chemistry”
1)
Longer
wavelength
Shorter
wavelength

6. So that means….
• When body temperature is warm
and the wavelength is shorter,
the stone will turn blue/ purple.
• When the person’s body
temperature is cooler, the stone
will turn a more reddish color

7. Microwaves (Tyson 1)
Why is this important?
Thermometers
Computer Screens

8. Works Cited!!!
Buthelezie, Thandi, et al. Light and Quantized Energy. Columbus: McGraw-Hill, 2008. Print.
Dowling, Martin. "How Mood Rings Work." Spectrumwellbeing.co.uk. Martin Dowling, 31 Jan. 2014.
Web. 3 Apr. 2014.< http://www.spectrumwellbeing.co.uk/aboutmoodrings.htm>.
"How the Chemistry of Mood Rings Works." Answers.com. Answers Corporation, n.d. Web. 26 Apr.
2014. <http://chem.answers.com/chemistry-basics/how-the-chemistry-of-mood-rings-works>.
Tyson, Jeff. "How LCDs Work." Howstuffworks.com. HowStuffWorks, n.d. Web. 9 Apr. 2014.
<http://electronics.howstuffworks.com/lcd.htm>.