Where Does Fire Go? | Science & Math Explained

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In summary, fire is the reaction taking place when the wax of a candle burns up the wick, producing iridescent chemical vapors. Snuffing the flame eliminates both the source of the vapors and the energy required to create a glow. Smoldering is when the reaction is progressing slowly and not producing enough heat to create flames. It requires oxygen, like fire, but removing oxygen will cause the embers to cool down and stop glowing. The glowing is a result of heat, not directly from fire.
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killza
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when u have a fire on a candle, and u blow the fire out, where does it go? does it evaporate into thin air? or does it just disappear? can fire really evaporate? i been wondering about this question ever since my math/science teacher brought it up
 
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The fire itself is the reaction taking place when the wax of a candle burns up the wick. I guess you could say the fire turned into smoke.
 
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"Fire" is simply iridescent chemical vapors. As long as the temperature is sufficiently high the vapors will glow, as soon as the temperature falls below some critical point the vapors will still be there but will not glow. Since the glowing vapors are a product of the chemical reaction occurring in the fuel, when the reaction halts so will production of the vapors. Thus snuffing the flame eliminates both the source of the vapors and the energy required to create a glow in the vapors.
 
  • #4
On a related note, what's the difference between something on fire and something smoldering?

If a log is in a campfire, it can either burn (fire) to ash, or smolder to ash. But it seems like fire is more than just heavy-duty smoldering. When the breeze blows, sometimes smoldering things catch fire. And often there's a sound associated with this.

Also, when you blow out a candle, sometimes the wick continues to smolder for a few seconds.

Does smoldering require oxygen like fire? I guess I could test this myself :devil: :eek:
 
  • #5
tony873004 said:
On a related note, what's the difference between something on fire and something smoldering?

If a log is in a campfire, it can either burn (fire) to ash, or smolder to ash. But it seems like fire is more than just heavy-duty smoldering. When the breeze blows, sometimes smoldering things catch fire. And often there's a sound associated with this.

Also, when you blow out a candle, sometimes the wick continues to smolder for a few seconds.

Does smoldering require oxygen like fire? I guess I could test this myself :devil: :eek:

I believe that smoldering means that the reaction is progressing slowing, not producing enough heat to create flames. Addition of [itex] O_2 [/itex] could change that.
 
  • #6
tony873004 said:
On a related note, what's the difference between something on fire and something smoldering?

I would call hot, glowing combusting gases 'flames', and hot glowing combusting solid carbonny stuff 'embers'.

Also, when you blow out a candle, sometimes the wick continues to smolder for a few seconds.

Yeah, it's still hot. Being solid, it takes longer to cool down than the gases, which are quickly cooled and dissipated.

Does smoldering require oxygen like fire?

You certainly need oxygen to have a fire. If you have no fire, you have no heat, and therefore you have nothing to make the embers glow. However, if you remove oxygen from a fire, the embers will continue to glow, but will cool down until they stop glowing.

The glowing isn't a direct result of fire, it's a result of heat.

Bear in mind that heating stuff up without oxygen will often also cause it to glow. The difference is that with no oxygen, no combustion is occurring, it's just hot and glowing. Fire requires oxgyen, since it's combustion. This happens to produce heat, which is why everything glows.
 

1. Where does fire come from?

Fire is a chemical reaction that occurs when a fuel source (such as wood, gas, or oil) combines with oxygen in the air and is ignited by heat or a spark. This creates a continuous reaction that releases heat and light, resulting in fire.

2. How does fire spread?

Fire spreads by transferring heat from the burning material to nearby combustible materials. This can happen through conduction (direct contact), convection (through the air), or radiation (through heat waves). The rate and direction of fire spread can also be influenced by factors such as wind and the type of material burning.

3. What happens to the air when fire burns?

When fire burns, oxygen in the air is consumed and converted into carbon dioxide, water vapor, and other gases. This is why fires can quickly deplete the oxygen in a confined space, making it difficult to breathe. The release of these gases also contributes to the heat and smoke of a fire.

4. How does fire create light?

Fire creates light through a process called incandescence. As the fuel burns, it releases energy in the form of heat and light. This energy excites the atoms in the burning material, causing them to emit light at different wavelengths. The color and intensity of the light depend on the type of fuel and the temperature of the fire.

5. Where does fire go when it is put out?

When fire is put out, it goes through a process called extinction. This means that the fire can no longer sustain itself due to a lack of fuel, oxygen, or heat. The remaining heat and smoke may dissipate into the surrounding environment, but the fire itself is no longer present. However, it is important to make sure that all embers and hot spots are fully extinguished to prevent the fire from reigniting.

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