My 9 year old is very fascinated by fire these days. He is also extremely into science (his teacher says he is on level with 14 year olds in his questions). The links here will be a great resource for me. :-)
Originally shared by Lacerant Plainer
What is fire, electricity and magnetism - and how are they related? : At the atomic level these are very different from what we would assume at the macro level. In some ways they are all related, since it has to do with the movement of electrons and creation of charge. When you see a match light, what happens is energy is released. While most of it is in the Infrared spectrum (What we call heat), there is also some of it released in the visible spectrum (light). The release is due to the Oxygen bonding with the material you are burning. While the effect may be too small to be seen in a matchstick, there is electricity and magnetism at work here too. You can see the effect on the Sun. Our Sun (or any star) is a miasma of incandescent plasma. One way to see this is to notice that the solar flares that leap from its surface are directed along the Sun’s (generally twisted up and spotty) magnetic fields. So what is this all about?
Electricity : The nucleus of an atom is surrounded by negatively charged particles called electrons. The negative charge of an electron is equal to the positive charge of a proton, and the number of electrons in an atom is usually equal to the number of protons. When the balancing force between protons and electrons is upset by an outside force, an atom may gain or lose an electron. When electrons are "lost" from an atom, the free movement of these electrons constitutes an electric current.
Different colors in flames : Electrons on atoms have different amounts of energy proportional to the distance of their orbital from the nucleus. Electrons (which are negative) close to the positive nucleus have lower potential energy; those in "higher" energy levels farther away have more energy. In order for an e- to "jump" from a lower level to a higher one it must absorb energy, often in the form of light. Conversely when an e- "falls" from a higher level to a lower one, it gives off energy, again in the form of a photon of light.
Magnetism : All materials experience magnetism, some more strongly than others. Both electric and magnetic interactions are elements of a single phenomenon called electromagnetism. There are four fundamental forces: the strong force, the weak force, gravitation and the electromagnetic force. The field of electromagnetism deals with how electrically charged particles interact with each other and with magnetic fields.
Electrons : The picture you often see of electrons as small objects circling a nucleus in well defined "orbits" is actually quite wrong. As we now understand it, the electrons aren't really at any one place at any time at all. Instead they exist as a sort of cloud. The cloud can compress to a very small space briefly if you probe it in the right way, but before that it really acts like a spread-out cloud. For example, the electron in a hydrogen atom likes to occupy a spherical volume surrounding the proton. If you think of the proton as the size of a grain of salt, then the electron cloud would have about a ten foot radius. If you probe, you'll probably find the electron somewhere in that region.
What is plasma : The big difference between regular gas and plasma is that in a plasma a fair fraction of the atoms are ionized. That is, the gas is so hot, and the atoms are slamming around so hard, that some of the electrons are given enough energy to (temporarily) escape their host atoms. The most important effect of this is that a plasma gains some electrical properties that a non-ionized gas doesn’t have; it becomes conductive and it responds to electrical and magnetic fields. In fact, this is a great test for whether or not something is a plasma.
References and links:
http://helios.gsfc.nasa.gov/qa_sp_ev.html
https://van.physics.illinois.edu/qa/listing.php?id=2348
http://physics.info/energy/
http://www.askamathematician.com/2011/01/q-if-atoms-are-made-up-of-electrons-protons-and-neutrons-and-the-majority-of-the-volume-of-an-atom-is-space-why-do-things-appear-solid/
http://www.physlink.com/Education/AskExperts/ae569.cfm
http://van.physics.illinois.edu/qa/listing.php?id=1195
https://www.uwgb.edu/dutchs/Petrology/WhatAtomsLookLike.HTM
http://www.askamathematician.com/2013/05/q-is-fire-a-plasma-what-is-plasma/
https://www.physicsforums.com/threads/a-description-of-fire-at-an-atomic-level.421438/
Pic courtesy : www.flavorage.com
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