Ultrasonic humidifiers are the quietest humidifiers available, and the ideal choice when noise level is a concern (if you are a light sleeper). In general, a warm moisture humidifier will be much quieter than a cool moisture evaporative humidifier.
Iodine is a chemical element with symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black metallic solid at a standard conditions that sublimes readily to form a violet gas. The elemental form was discovered by the French chemist Bernard Courtois in 1811.
When a solid turns straight into a gas, it is called sublimation. Examples of substances that sublime include carbon dioxide, iodine, arsenic, and naphthalene. Only certain solids evaporate. Most solids melt before evaporating. When a solid turns straight into a gas, it is called sublimation. Examples of substances that sublime include carbon dioxide, iodine, arsenic, and naphthalene. Only certain solids evaporate.