Mood jewelry is made from either a clear capsule filled with thermo chromic liquid crystal, or a thin sheet of liquid crystal paint that is sealed underneath a plastic or glass dome. Mood jewelry change colors by the same principle as a liquid crystal thermometer.
A senatorial candidate must be 30 years old to qualify for election. Candidates for the House of Representatives must be 25 years old to qualify for election. Presidential and vice-presidential candidates must be 35 years old. A senatorial candidate must be 30 years old to qualify for election.
Many states require elected municipal officers to be at least 18 years of age or be a registered voter in the city thereof. Montana requires mayors to be at least 21 years of age. As of November 2016, most U.S. cities with populations exceeding 200,000 required their mayor to be a registered voter in the city thereof or at least 18 years of age.