There are two main types of soft solder; lead solder and lead-free solder. Lead solders have about 60% (or 63%) tin and 40% (or 37%) lead in them. They are toxic because they have lead in them. They melt at around 185°C. Lead solder is cheap, so it used to be popular. In plumbing, a 50% tin and 50% lead mixture was used. People thought this was safe, but then they saw that the lead was coming into the water. Now lead solder is illegal for water. Lead solder was once used for food cans. After many years, the lead could come into the food. The cans poisoned people who ate the food. Lead solder is still used in electronics.
In 2006 the European Union, China, and California banned lead in consumer products. Lead solder became illegal in electronic devices in some places. Lead-free solder was needed. Many lead-free solders have tin, silver, and copper in them. They melt around 217°C. Sometimes indium is added to the solder to make it better, but indium is very expensive.
Many times when a metal is being soldered, it oxidizes, making a layer of metal oxide that does not hold solder. Flux is added to react with the metal oxide and turn it back into the metal again. That helps the solder connect to the metal. Rosin is a common flux. Some electronics makers use fluxes that can be washed away with water. Some solders have a flux core, where the flux is inside the solder.
Another type of solder is used to connect glass to other things. They melt around 450-550°C.
Frame-dragging
Frame dragging is a theory which says that space is elastic, and particles in it will exchange energy with it. In the scientific world, "elastic" means that when you apply a certain amount of force to an object (which will cause it to bend) and then remove the force, the object will return to its original shape and energy state. Also, space is referred to as spacetime, which is simply a way to bring together the concepts of space and time. This basically means that whenever space is affected, time is affected. Frame dragging would provide answers for very old questions about gravity, strong force, and wave-particle duality (how things like electrons can act like waves and particles at the same time).
In frame dragging, particles spin, and this spin has energy in it. (It is important to note that this is not quantum physics spin, but an actual angular momentum spin; the particles are actually spinning). Since spacetime is elastic in this theory, it can absorb the energy (spin) of the particle. This would slow down the spin of the particle.
Mass has a strange effect that we experience in the normal world: it attracts other mass. Scientists have been spending centuries trying to explain this occurrence. Recently, they have discovered that mass has an effect that it can curve spacetime. This means that when mass is present, the shortest path through spacetime between two points is slightly bent towards wherever the mass is.
Since the energy absorbed by spacetime has to go somewhere, many scientists predict that spacetime would be "bunched up," or folded. This can also be phrased as a curvature (bend) in spacetime. This would indicate that the particle generated gravity. The reason that this theory is called "frame dragging" is probably due to the effect of particles effectively "dragging" or "grabbing" spacetime as they spin. Not only would space be curved, but time would as well.
However, the way to imagine this "gravity" is not so much as the force that we normally consider when we think of gravity, since normal gravity is created as well (due to its mass). Basically, frame dragging is an effect that occurs when one object is moving near another, which makes both objects change their motion because of the other's motion. Frame dragging does not occur if an object is neither spinning nor moving. In effect, one object "deflects" the motion of the other, and the other way around.
Scientists such as Einstein and Schrödinger spent much of their lives trying to find an answer for how something like an electron can act like a wave and also act like a particle. Frame dragging states that since spacetime is elastic, it can also give the spin-energy back to the particle. Once the particle has all of its spin-energy given back to it, it acts most like a wave. At that point, it will once again begin using its energy bunching up spacetime. Once the particle is no longer spinning, it acts most like a particle. Then, spacetime begins giving the particle its energy back, and the cycle continues forever. This is how a particle can actually act like a particle and a wave at nearly the same time. No energy is lost during the cycle due to the conservation of energy.
Frame dragging also has an effect that if one particle is next to another, they can both save energy if one is absorbing energy as the other one is emitting it. (This can also increase the mass of both particles, using Einstein's famous equation that energy is equal to a certain amount of mass). This would encourage particles to group together, which would explain what strong force (a force that holds protons and neutrons in an atom nucleus together) is.
There are effects that come out of the math of the frame dragging theory. Scientists are currently testing one which is that if one small spinning object is orbiting a larger spinning object, the smaller object will slowly adjust its spin axis (the imaginary line which an object rotates around) to align with the larger object's spin axis. This is known as the Lense-Thirring effect. They are testing this theory by having a gyroscope (an object that will normally keep its spin axis the same) orbit the Earth, and testing whether its spin axis will align with the Earth's spin axis. So far, scientist say that they have evidence that proves the Lense-Thirring effect (and possibly the frame dragging theory) to less than .5% accuracy.
Antimony pill
An Antimony pill is a pill made from metallic antimony. It was a popular remedy in the nineteenth century, used to purge and revitalise the bowels. In use, it is swallowed and allowed to pass through the body, after which it is recovered for reuse. They called it the everlasting pill.
Aluminium antimonide
Aluminium antimonide is a chemical compound. Its chemical formula is AlSb. It has aluminium and antimonide ions in it. Compounds like it, such as gallium antimonide and indium antimonide can be made into LEDs and detectors for Infrared radiation but aluminium antimonide doesn't work as well. It is used instead to make the other compounds work better by stopping defects forming as they are made.
Aluminium antimonide is a black solid. It is a semiconductor. It reacts with acids to make stibine. It is a reducing agent. It has properties between a salt and an alloy.
Antimonide
Antimonide is an ion. Its chemical formula is Sb. It has antimony in its -3 oxidation state. Antimonides are reducing agents. They react with acids to make stibine. Many antimonides have properties between a salt and an alloy. Many transition metal and post-transition metal antimonides are semiconductors.
Stibine
Stibine, also known as antimony hydride or hydrogen antimonide, is a chemical compound. Its chemical formula is SbH. It is a covalent compound. It could be seen as having antimonide and hydrogen ions, or antimony and hydride ions.
Stibine is a colorless gas. It is very toxic. It has a bad smell like hydrogen sulfide. Its structure is similar to ammonia. It can be found in the Marsh test, a test for arsenic. Antimony is reacted with a mixture of zinc and hydrochloric acid in a tube, making stibine. The stibine is heated and a shiny area of antimony is made in the heated part of the tube.
Stibine easily decomposes into antimony and hydrogen at room temperature. This decomposition can be explosive. It burns very easily in air to make antimony trioxide and water. It can be deprotonated by very strong bases. Stibine melts at -88°C and boils at -17°C.