Almost everybody on our planet is familiar with the smell of ozone: it is the smell we notice after a thunderstorm. But do you know the reason for it?

Here is the explanation: an electrical charge of lightning splits the molecules of oxygen (O2) into single atoms (O) and then some of these single atoms combine into ozone molecules (O3). That is why we feel the specific smell associated with a thunderstorm.

It is good that only some atoms of oxygen combine into a group of three, because too much ozone is dangerous for our health: this gas is a strong oxidizer and large amounts of it may do harm to our trachea and lungs and even prove fatal.