Because the flame doesn’t only need oxygen. It also needs fuel to react with that oxygen and it needs the reaction of the fuel with the oxygen to release energy overall.
When you are burning something in the air, you’re burning *something* — that is, a fuel. The reason all the nearby stuff doesn’t catch on fire as soon as you strike a match is that all of the nearby stuff doesn’t react with oxygen in the air in a way that releases energy unless it gets hot enough, and it isn’t hot enough. Of course, if it’s close enough to a flame, then it too can burn because the flame is heating it up to a temperature where it will react with the atmosphere.
Because the flame doesn’t only need oxygen. It also needs fuel to react with that oxygen and it needs the reaction of the fuel with the oxygen to release energy overall.
When you are burning something in the air, you’re burning *something* — that is, a fuel. The reason all the nearby stuff doesn’t catch on fire as soon as you strike a match is that all of the nearby stuff doesn’t react with oxygen in the air in a way that releases energy unless it gets hot enough, and it isn’t hot enough. Of course, if it’s close enough to a flame, then it too can burn because the flame is heating it up to a temperature where it will react with the atmosphere.
A flame is the result of combustion and it needs a fuel and an oxidizer.
The oxidizer is usually oxygen and there the atmosphere is 21% oxygen.
The rest of the atmosphere 78% nitrogen 1% argon and 0.04% other gases. Neither nitrogen or argon can be the fuel and burn with oxygen.
If we list the other gases in how common the are until we get one that can burn: Carbon dioxide, Neon, Helium and Methane.
Methane is the most common gas in the atmosphere that works as a fuel and its concentration is 0.000187% That is simply not enough to sustain combustion and even if it was possible you only use need a bit less the 2/3x the amount of oxygen. The result is 0.0005% of all atmospheric oxygen will be used up when all methane has combusted.
Because the flame doesn’t only need oxygen. It also needs fuel to react with that oxygen and it needs the reaction of the fuel with the oxygen to release energy overall.
When you are burning something in the air, you’re burning *something* — that is, a fuel. The reason all the nearby stuff doesn’t catch on fire as soon as you strike a match is that all of the nearby stuff doesn’t react with oxygen in the air in a way that releases energy unless it gets hot enough, and it isn’t hot enough. Of course, if it’s close enough to a flame, then it too can burn because the flame is heating it up to a temperature where it will react with the atmosphere.
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