Light a candle, let it burn for a while, and blow it out again. White smoke rises from the wick. If you hold a burning match in the smoke, a jet of flame shoots down to the wick, and it re-lights.
After the flame is blown out the steam is still so hot that it continues to evaporate and produce a vapor. But as this is combustible, it can be re-lighted at once by a naked flame. The experiment shows that solid substances first become gaseous at the surface before they will burn in a supply of oxygen.
No comments:
Post a Comment