IS FIRE A SOLID OR A GAS?
The two words "fire" and "safety" go hand in hand. Every sensible person knows that fire is not something to play with, and that whenever we use it we need to exercise a great deal of caution. When we are finished we put the fire out completely to make sure there is no smoldering afterglow to spring up later on.
Our world is made of solids, liquids and gases, and these things are made of `invisibly small atoms and molecules. This statement may be a bit misleading because it does not include happenings. In a fire, solid logs burn and give off sooty smoke, invisible gases and gritty ashes. Yet the fire itself is none of these things. It is a chemical happening that uses energy to change solids into gases and other substances.
Countless different chemical reactions go on all the time throughout the world of nature. All of them are busy rearranging atoms to create different molecules of one substance or another. In the process some of the chemical reactions use energy, while others give off energy. When a blazing fire rearranges the molecules of a fuel, it gives off energy in the form of heat and light.
The logs used to light a campfire come from a tree that was once a tiny seedling. As the seedling grew, it used atoms from the air, water and dissolved chemicals to build woody molecules for its trunk. Naturally the work of building molecules to form the boxy tree cells required energy--which was supplied by the sun.
When the tree is cut down, the logs can be used as afuel. However, it takes more than just fuel to have a fire. You must also have heat and lots of airy oxygen. A wad of burning paper provides enough heat to start smallish branches burning: the branches provide enough heat to cause the logs to burn, and soon we have a roaring campfire. The heat of the fire releases the energy that bound the woody molecules together and is given off as heat and light
Countless different chemical reactions go on all the time throughout the world of nature. All of them are busy rearranging atoms to create different molecules of one substance or another. In the process some of the chemical reactions use energy, while others give off energy. When a blazing fire rearranges the molecules of a fuel, it gives off energy in the form of heat and light.
The logs used to light a campfire come from a tree that was once a tiny seedling. As the seedling grew, it used atoms from the air, water and dissolved chemicals to build woody molecules for its trunk. Naturally the work of building molecules to form the boxy tree cells required energy--which was supplied by the sun.
When the tree is cut down, the logs can be used as afuel. However, it takes more than just fuel to have a fire. You must also have heat and lots of airy oxygen. A wad of burning paper provides enough heat to start smallish branches ,burning; the branches provide enough heat to cause the logs to burn, and soon we have a roaring campfire. The heat of the fire releases the energy that bound the woody molecules together and is given off as heat and light.
The fire itself is neither a solid nor a gas, and it's certainly not a liquid. It is an energetic happening that releases energy bound up in the molecules of a fuel.
Just as heat, oxygen and a fuel are necessary to start a fire, you can put out a fire by removing one of the three. When water is sprayed on a wood fire it absorbs heat from the burning wood and lowers its temperature. When the temperature falls below the kindling temperature, the fire goes out
Some fires cannot be put out with water. In fact, in some cases it is downright dangerous to use water. Grease or oil will float on water and water can actually cause them to spread. It is also dangerous to use water on an electrical fire.