what is the ingredient in onions that makes your eye's water?

Answer 1

It is the sulphur compounds.

One way to keep this from happening so fast, is to make sure that the onion is very cold before you cut it up. When the molecules are cold, they don't disperse into the air as fast, and you can almost always chop them completely before you even have one tear.

Answer 2

Onion contain a substance Called a lachrymator, which is released into the air when the vegetable is peeled or cut. When these vapors combine with moisture from your eyes, sulfuric acid is formed, resulting in a painful burning sensation and tears.

Good luck! _;-)

Answer 3

http://www.loc.gov/rr/scitech/mysteries/onion.html

A link for your perusal. If however you put an onion in the fridge for a couple of hours before you need to chop it, the fumes are much weaker.

Answer 4

sulpheric acid