It's Valentine's Day, and no doubt you have heard that "love is in the air."
You've also likely caught whiffs of fragrant bouquets throughout the day, or savored the tantalizing aromas of chocolate from heart-shaped boxes.
But did you know that in addition to love -- and all the scents associated with it -- air also contains a multitude of other gases?
We need oxygen to live, but it's only 21 percent of the air we breathe
On a daily basis, about 99.9 percent of the air in the atmosphere consists of a fixed amount of nitrogen, oxygen and argon.
In fact, 78 percent of the air we breathe consists of nitrogen; oxygen only makes up 21 percent. The remaining 1 percent of air is mostly argon, and a tenth of a percent of the air consists of a variable mixture of the following: carbon dioxide, neon, helium, methane, nitrous oxide, ozone.
The atmosphere also contains water vapor, which is the gaseous form of water. However, depending on the day and location, the amount of water vapor in the air can be less than one percent (ie, in the cold, dry areas of the north and south poles) or as high as 4 percent (ie, in the warm, humid regions of the tropics). The transport of water vapor ahead of a storm system provides the "fuel" for the storms.