Do flames contain plasma?
Answers
Answer:
A textbook definition of a plasma is an ionized gas. "Ionized gas" means that some electrons have been ripped completely off the atoms that make up the gas. The effectively-free electrons are negatively charged and the resulting ionized atoms end up positively charged. An "ion" is an atom with an unequal number of electrons and protons. This definition is a good starting point, but it is not exact enough. Every gas contains a few ions and freed electrons, and yet not every gas is a plasma. There must by some cutoff point where there are enough ions in the gas that it begins acting like a plasma.
The bottom line is that a flame only becomes a plasma if it gets hot enough. Flames at lower temperatures do not contain enough ionization to become a plasma. On the other hand, a higher-temperature flame does indeed contain enough freed electrons and ions to act as a plasma.
A candle flame is therefore not a plasma