What is fire made of

The sides of the triangle represent the interdependent ingredients needed for fire: heat, fuel and oxygen. A heat source is responsible for the initial ignition of fire, and is also needed to maintain the fire and enable it to spread. Heat allows fire to spread by drying out and preheating nearby fuel and warming surrounding air.

Fuel is any kind of combustible material. The moisture content determines how easily it will burn. Air contains about 21 percent oxygen, and most fires require at least 16 percent oxygen content to burn. 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. Then move on to denser woods, like oak. These take a lot more energy to start burning and will burn longer.

When it gets going, a fire is like a living thing. It needs to be fed, sustained, and looked after, or it will die. You can find plenty of diagrams for building campfires: teepee designs , log cabin designs, elaborate plans for digging underground air-intake vents. This rule comes from Bejan, who thought of it while watching a mound of charcoal ignite in his backyard grill. He realized when a fire is built into a pyramid shape, it will burn the hottest for the longest amount of time.

The extreme is to have a skinny, stick-like pile. That, too, is a bad design. Bejan published this finding in the journal Scientific Reports.

To him, the universality of the fire shape is evidence that humans have an innate sense of physics. If a fire burned perfectly, the log would be completely torn down into carbon dioxide and water vapor. But most fires do not burn perfectly. And as a result, wood smoke contains a lot of pollutants: chemicals like benzene and formaldehyde, as well as fine particles that can irritate lungs and eyes. As Brad Plumer has explained, indoor air pollution from wood smoke is the deadliest environmental hazard on the planet.

But the hotter a fire burns, the more these toxic chemicals can get broken down into simpler, safer ones. Burning dry wood also helps keep these pollutants to a minimum. Fine particles from the smoke and soot can be smaller than 2.

Fine particles also can aggravate chronic heart and lung diseases — and even are linked to premature deaths in people with these conditions. The particles from wood smoke also can contribute to smog and haze. In Minnesota, for instance, where recreational outdoor fires are popular, Herschberger says recreational wood smoke accounts for around 5 percent of all the fine particles released to the air.

In terms of carbon dioxide emissions, wood smoke can be carbon neutral if the wood you burn is replaced by new growth. On the small scale, fire is predictable.

It makes fire on a mountainside absolutely magical, unpredictable. Like dark magic? With ongoing drought, climate change, and, ironically, a history of fire suppression , forest fires in the Western US have been growing bigger and more destructive over time. A lot of these fires are started by lightning. But as Smokey the Bear has cried for decades, you can help prevent forest fires.

A marshmallow is made up of gelatin and sugar. Sugar burns at around degrees Fahrenheit. A campfire can top more than 1, degrees. Our mission has never been more vital than it is in this moment: to empower through understanding. Financial contributions from our readers are a critical part of supporting our resource-intensive work and help us keep our journalism free for all.

In complete combustion, the burning fuel will produce only water and carbon dioxide no smoke or other products. The flame is typically blue. For this to happen, there needs to be enough oxygen to combine completely with the fuel gas. Many of us use methane gas CH 4 , commonly known as natural gas, at home for cooking.

When the gas is heated by a flame or spark and if there is enough oxygen in the atmosphere, the molecules will break apart and reform totally as water and carbon dioxide.

If there is not enough oxygen available during a chemical reaction, incomplete combustion occurs, and products such as carbon C and carbon monoxide CO as well as water and carbon dioxide are produced. Less heat energy is released during incomplete combustion than complete combustion. Wildfires — what are they? What causes them? How do wildfires impact us and are they affected by the climate?

Drama in the microworld — using drama to model atoms, molecules, heat transfer and combustion. Light a candle — observe and investigate a candle flame and the process of burning. Putting out the fire — investigate ways of extinguishing fire, using knowledge of the fire triangle and fire chemistry. Exploding flour — observing combustion. Add to collection.