Why do Onions make us cry ???

Onions are rich in nutrients including vitamins B and C, protein, calcium and iron.

It is not the strong odour of the onion that makes us cry, but the substances that the onion releases when we chop it. The vegetable contains some sulphur compounds which are released when chopped. Sulphur being an irritant to both our nose and eyes, makes tears flow out.

What actually happens:

When the sulphur compound comes in contact with the water in our eyes, it produces very dilute sulphuric acid. This acid then irritates the eyes. In response to this acid, our eyes automatically blink and produce tears, which wash the eye and flush out the acid.