A corn kernel pops at about 180 °C, when the water inside it turns into steam.
Why it is true
The hard hull keeps the steam trapped, and the pressure rises to about nine times that of the air. When the hull gives way, the softened starch suddenly expands into a foam that cools and sets. The pop is heard as the steam escapes.
Source: Journal of the Royal Society Interface (Virot & Ponomarenko, 2015)
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.
