SCIENCE
PHYSICAL SCIENCES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Air is both flammable and combustible.
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Air causes a physical change in the wood of the burning trees.
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More gases become involved, so several additional chemical changes occur.
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More oxygen is supplied to the chemical reaction.
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Detailed explanation-1: -Oxygen supports the chemical processes that occur during fire. When fuel burns, it reacts with oxygen from the surrounding air, releasing heat and generating combustion products (gases, smoke, embers, etc.). This process is known as oxidation.
Detailed explanation-2: -Oxygen is not flammable, but fire needs it to burn. ➢ When more oxygen is present, any fire that starts will burn hotter and faster than usual.
Detailed explanation-3: -If the oxygen level is below 15% in the atmosphere, it does not support fire. If the oxygen level is above 25%, it would cause forest fires and other types of fires which are impossible to put out.
Detailed explanation-4: -As you figured out, blowing on the embers increases the rate they burn, by getting more oxygen to the site where oxygen reacts with the carbon compounds. What happens with the candle? The candle already has a lot of oxygen available.