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.
The mass number for iodine is 131, which is the sum of the protons  and neutrons. Iodine has 53 protons and 53 electrons, if neutral.  To find how many neutrons iodine has s â¦ ubtract 53, the number of  protons from the mass number of 131. This shows that iodine has 78  neutrons.