Film title: What is burning?
Forest fires can spread dramatically, burning huge numbers of trees in just minutes.
But what is burning?
What is burning?
Burning is a chemical reaction that needs three things to make it happen.
Material to burn, called the fuel, a supply of oxygen, and a source of heat to set fire to, or ignite, the fuel.
fuel
oxygen
heat
A forest fire uses trees as its fuel and oxygen from the air.
The heat needed to ignite the trees may come from a lightning strike or a dropped cigarette...
But once established, the fire itself produces the heat needed to burn more trees.
The heat and light energy released during burning come from energy stored in the trees.
Chemical reactions that release energy are known as exothermic reactions.
burning
exothermic reaction
releases heat and light energy
You can stop any fire if you take away one of the three ingredients.
Fire fighters can't take away the oxygen in the surrounding air, but they can take away the heat by spraying huge amounts of water over the fire.
Or they can take away the fuel, by creating treeless areas called firebreaks.
firebreak
When the fire reaches this break it burns itself out because it runs out of fuel.
During the fire the trees are used up but new substances have been produced.
Gases and smoke in the air and ash on the ground.
It may seem that the fire has destroyed everything ... but now, with no trees blocking sunlight, seeds in the forest will grow into new trees, and in time the forest will recover.
burning
fuel
oxygen
heat sources
But what is burning?
What is burning?
Burning is a chemical reaction that needs three things to make it happen.
Material to burn, called the fuel, a supply of oxygen, and a source of heat to set fire to, or ignite, the fuel.
fuel
oxygen
heat
A forest fire uses trees as its fuel and oxygen from the air.
The heat needed to ignite the trees may come from a lightning strike or a dropped cigarette...
But once established, the fire itself produces the heat needed to burn more trees.
The heat and light energy released during burning come from energy stored in the trees.
Chemical reactions that release energy are known as exothermic reactions.
burning
exothermic reaction
releases heat and light energy
You can stop any fire if you take away one of the three ingredients.
Fire fighters can't take away the oxygen in the surrounding air, but they can take away the heat by spraying huge amounts of water over the fire.
Or they can take away the fuel, by creating treeless areas called firebreaks.
firebreak
When the fire reaches this break it burns itself out because it runs out of fuel.
During the fire the trees are used up but new substances have been produced.
Gases and smoke in the air and ash on the ground.
It may seem that the fire has destroyed everything ... but now, with no trees blocking sunlight, seeds in the forest will grow into new trees, and in time the forest will recover.
burning
fuel
oxygen
heat sources
What are the three factors needed to make something burn?
Learning points
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