There are 2 iron balls one is coated with  alluminum, one isnt. When they collided there was a spark,Why?
929210
You are exactly right. The energy given to the system when you hit them together was enough energy to break the bonds of the oxide layers on top. The thermal energy of the reaction elevated the electron energy states for a small amount of time, causing them to fall back down to their ground state and giving off some photons...hence the spark.
615674
dry air conducts static electricity better, and a spark might case a fire???\n\ni know that was the case in old flower mills
728971
(The) second experiment was to observe the reaction when a magnesium ribbon was ignited. The ribbon was put to the flame of a burner (delete ,) and was ignited. The reaction was very (intensive) (change to intense), and (burned with a) (delete was with) very bright white light. Usually when a substance is ignited in air, it reacts with H2 or O. In this case, because the Mg was the positive ion, it must have reacted with oxygen, (which is a ?)negative ion. In this experiment, because Mg was joined to O2 to make 2MgO of different composition, this was a combination reaction.\nThe third experiment 0.1 M CuSO4 and 6 M NH3 were used. CuSO3, a Sky blue liquid,  was place in a test tube, and then 1 drop of 6 M NH3 was added. Right after NH3 was added, the top of (the) liquid changed to navy color.  After the liquid was stirred the color of the liquid changed to a blue that was darker than the color of CuSO3. Ten more drops (of CuSO4?) were added to the contents, and the color of (the) contents changed to a violet color.
1039184
This is great!!! He was on ludes... How would it have been to have a metal hemaroid?
134024
Most students of the modern Life Saver classify sparking as a type of triboluminescence, which occurs when something is crushed or torn, the something in this case being the hard crystalline sugar that Life Savers contain. (Another example of TL is the spark you get when you tear the piece of tape off the end of a roll of photographic film.)\n\nWintergreen sparking, it's believed, is actually a three-step process. Step One: When you shatter the sugar crystals with your teeth, electrons (which are negatively charged) break free. As a result, the atoms in which the electrons were formerly embedded become positively charged. In what amounts to a subatomic game of musical chairs, the free electrons dash around madly trying to find a new home.\n\nStep Two: Meanwhile, as the sugar crystals disintegrate, nitrogen molecules from the air attach themselves to the fractured surfaces. When the free electrons strike the nitrogen molecules, they cause the latter to emit invisible ultraviolet radiation, along with a faint visible glow.\n\nStep Three: The UV radiation is absorbed by the wintergreen flavoring, methyl salicylate. This then emits the fairly bright blue light you see. Pretty complicated, I admit. Clearly the planners in the Pentagon weren't the first to be obsessed with high-tech gimcracks.
431850
No.  A spark would require oxygen
10553
you are speaking of the collision ball apparatus and not the Gravesande Apparatus I assume.\n\nThe reason has to do with newton's law...\nThe force transfers from one end to the other and causes the same MASS to move the same distance (minus friction)\nif the first ball was twice the MASS of the rest of the balls, then dropping that one ball would cause 2 balls on the other end to move.. and conversely, dropping 2 smaller balls would make the one larger ball move.\n\nA = F/M
920713
A spark of static electricity caught some leaking hydrogen on fire.  The skin of the ship was made of aluminum oxide which some solid rockets use for fuel today, so that burned pretty quickly and caught the rest of the ship on fire.  The static electricity is said to have been caused by some bad weather.
263570
Instances of "ball lightning", or at least phenomena that might well be construed as ball lightning, have been observed for hundreds of years. It is indeed likely that many historical (or contemporary) accounts relating to magic or UFOs may well be related to this natural phenomenon. Despite these many years of precedent, however, it is only over the past few decades that scientists have begun to take ball lightning seriously.\n\nClick here for a short educational film.\n \nInformation about ball lightning (as no theory has been confirmed as the 'definitive answer') comes mostly from eye-witness reports. Unfortunately, these sightings vary wildly in content, perhaps indicating that there are different kinds of ball lightning stalking the people of Earth.\n \nIn May of 1949, several farm labourers were gathering the asparagus harvest in Rushford, England. Peggy and Delia Filby were among those who took refuge from a rainstorm by sheltering themselves within a tarpaulin covered trailer. During the height of the thunderstorm, a brilliant flash rocked the area indicating a heavy lightning strike. Delia and others then saw what they described as a "football-sized, softly glowing orange-red ball of light". It gave off neither sparks nor rays, and did not pulse as it bounced across the field, towards the frightened observers. Within a few seconds, however, the ball disappeared soundlessly. The workers experienced something like an electric shock as it did so.\n \nIn 1967, M. Dmitriev, a Russian chemist, was camping on the banks of the Onegaw river. Following an intense lightning flash, a "ball of fire" appeared about 30 cm over the surface of the water, unaffected by the intense winds. The ball crackled and hissed as it flew past his head and into a group of nearby trees. The sphere bounced from tree to tree "like a billiard ball", emitting a trail of blue-grey smoke.\n \nOne of the most (in)famous ball lightning sightings comes from Roger Jennison, professor of Electronics at the University of Kent. In March of 1963, while caught in a storm en route from New York to Washington, his plane was enveloped by a bright and audible electrical discharge. Some seconds later, a glowing sphere emerged from the pilot's cabin and passed through the central aisle of the aeroplane, from one end to the other. The ball floated at about 75 cm above the floor, and moved at approximately 1.5 metres per second (relative to the aircraft). It gave off no discernible heat, and was an opaque, blue-white colour.\n \nFrom these accounts and others, scientists have come to understand that ball lightning typically occurs shortly after 'normal lightning', although it has been known to arise several days after such a lightning strike. It appears able to pass through glass and solid objects, sometimes causing damage in the process, and only rarely emits heat. Sometimes a hissing or crackling sound can be heard, other times it is perfectly silent.\n \n \nBall Lightning origin theories from AA&ES Magazine.\n \n"A simple answer to the phenomenon doesn't appear to be forthcoming and tentative explanations rely heavily on theoretical physics. One of the current favourites concerns electromagnetic plasmoid models: the greatest problem for the theorist is explaining how sufficient energy be contained within such a small space without it being emitted steadily and continuously, but sometimes suddenly. Dr. Geoff Endean (School of Engineering and Computer Science, University of Durham) has suggested that the energy containment problem can be circumvented since a very rapidly rotating electric field can exist in a plasma without a magnetic field with no apparent limit to the electrical field strength - heady stuff indeed.\n \nFurthermore, it has also been suggested that ball lightning may occur quite frequently but the electromagnetism associated with it is not strong enough to render it visible to the eye
1151741
It's questionable. It seems it was hit with some sort of missile. The story is supposedly that an airplane hit it, but the resulting hole is too small and there is no evidence of plane. The government says the explosion was so hot it burned the evidence, but how come the bodies and other things around weren't burned? It's one of the many questionable topics of 9/11 (like how the twin towers free-fell to the earth??) that are explored in the video below.
658125
It has it's flammable state...Try to imagine it as a fuel air bomb.Thn there you will get your Idea.
928895
It would be Iridium and if you need a small sample of it, they use very very small amounts of it in spark plugs because it supposedly produces better spark and combustion.
1167454
Usually, you shoot a high energy neutron at it.  It's like in pool, when you break in billiards.  You shoot one ball very fast at the pile of balls, and then they break apart.
266957
The PHYSICAL PHENOMENON here is called ELECTROSTATIC SHIELDING!\n\nIt says that electrostatic field inside a hollow metal conductor is ZERO! \nThe field will be zero even if the conductor encloses a charge!\n\nHere the CAR can be considered as the conductor,\nSo! even if there is  a million volts of lightning outside! You are safe inside!\nThanks- Hope I helped\nPeace!
81359
rust is actually iron deposits from contact with  water and oxygen and iron is metal which can cause sparks but its not really dangerous your microwave wont explode like it does in the hollywood movies but i do suggest you get a new one if its a bad case of rust such as the entire side or even half the side of the microwave i dont think that all that iron could be good when it gets on your food.
617094
Probably some of the aluminum caught fire in the fireball from the burning hydrogen.  If so, the reaction would be:\n\n4 Al +  3 O2 =====> 2 Al2O3
279303
I'm not sure what you're angling for, but it did get\nme thinking.\n\nSomeone else offered a gun/bullet combination, which could\npossibly qualify since the *bullet* is non-mechanical\nand engine-less.  The bullet is "man made" in that the\nlead was shaped by man.  Seems to me like its worst\noffense is that the the gun is mechanical and has moving\nparts.\n\nAnyway, consider a cyclotron.  To the best of my knowledge,\nit has no moving parts except for the magnetically\npropelled projectiles.  Once the charged particles\nare smashed together, they produce new particles -- in\na sense, these new particles are man made (ie. because\nthey didn't exist before men made them from other\nparticles).\n\nThe interesting thing about this example, though, is that\nthese objects can leave the point of impact at pretty\nclose to the speed of light.  This may not fulfill your\nrequirements, but I doubt you'll find anything faster :-)