What is the difference between fire and electricity? What is the role of electricity in combustion? Why is electricity prone to cause fires?

Asked by: Jeremy Allen

Answer

Electricity is the transfer of electrons along a wire, fire is the reaction of a substance with oxygen.

A yellow flame, as usually observed, is an area filled with hot carbon particles, that can cause other substances to ignite. An electric spark is an area where the air conducts electricity by ionization. These sparks may ignite combustible materials. Also, a wire that has a current flowing through it, may heat-up and cause the temperature to rise sufficiently to ignite materials. This heating up effect is more severe when the current (I) is higher, so in a short-circuit circumstance (where the resistance of a circuit becomes nearly zero and the current blows up according to V = IR) the heating may cause a fire, which is the main electricity fire hazard in households.
Answered by: Alex de Beer, Student

There is all the difference in the world between electricity and fire. Fire is the result of a chemical reaction, a chemical reaction that produces heat and light. Not all chemical reaction produce heat and light and some only produce heat and some only produce light. Electricity is the result of charged particles either in motion (an electrical current) or not (static electricity).

In most cases for a fire to start there must be a quantity of heat energy available to get the chemical reaction started. Once started the chemical reaction can sustain itself until it runs out of fuel or oxygen.

In most cases an electrical current will produce heat and if it produces enough heat it can start the combustion process and there is a fire. Static electricity can produce a lot of heat when it discharges. The best example of this is lightening. This too can start a fire.

So, electricity can start a fire only if it produces enough heat to get the chemical reaction going. But the two, electricity and fire, are still very, very different from each other.
Answered by: Tom Young, Science Teacher at Whitehouse H.S.