Agave nectar (sometimes called agave syrup) is most often produced from the Blue Agaves that thrive in the volcanic soils of Southern Mexico. Agaves are large, spikey plants that resemble cactus or yuccas in both form and habitat, but they are actually succulents similar to the familiar Aloe Vera.
Quick Answer. The instruments that measure water vapor content in the air are called a hygrometer and psychrometer. Water vapor is water suspended in the atmosphere in the form of an invisible gas. Humidity is the measure of water vapor content of the air. Continue Reading
But, the water that makes the air humid isn't liquid. It's water vapor, which is a gas that is lighter than nitrogen or oxygen. (Related: Understanding water in the atmosphere). Compared to the differences made by temperature and air pressure, humidity has a small effect on the air's density. But, humid air is lighter than dry air at the same temperature and pressure.