Question

what is the state of matter of fire

Answer 1

Fire is an oxidizing chemical reaction that releases heat and light. The actual flames that you see moving and glowing when something is burning are simply gas that is still reacting and giving off light. Plasmas are gases in which a good fraction of the molecules are ionized. Ordinary flames ionize enough molecules to be noticeable, but not as many as some of the much hotter things that we usually call plasmas.  (See  for a guide to an experiment that uses the electrical conductivity of a flame caused by its ions.)

Of course, plasma and fire can both radiate visible light, So what's the big difference between an intense plasma and the weakly ionized gas in an ordinary flame? Plasma arc welding () offers a good example of plasma and its qualities in comparison to ordinary flames. In plasma welding, gas is plasmized via an electrical current and in the process heated up to 20,000o Celsius and shot onto a material. The plasma gives off ultra-violet rays which can blind the welder if not protected, and cause tissue damage to bystanders. 

Answer 2

Fire is an oxidising chemical reaction that releases heat and light . The actual flames that u see moving and glowing when something is burning are simply gas that it still reacting and giving of light. Plasmas are gases in which a good fraction of the molecules are ionized .