.... orbital radius. When atoms bond together to form a solid, the electron energy levels merge into bands. In electrical conductors, these bands are continuous but in insulators and semiconductors there is an "energy gap", in which no electron orbits can exist, between the inner valence band and outer conduction band [Book 1]. Valence electrons help to bind together the atoms in a solid by orbiting 2 adjacent nucleii, while conduction electrons, being less closely bound to the nucleii, are free to move in response to an applied voltage or electric field. The fewer conduction ele .....

.... colour (or energy). ¨ travels at a speed of 2.99792458x10^{8} ms^{-1} ¨ When passing though matter, is slowed down by brief interactions, and so appears to travel more slowly. ¨ This "slowing down" is accounted for by the index of refraction of the matter. 's properties can at first seem confusing and inconsistent because of the unique nature of light: light has the properties of both a wave and a particle. In some situations, light's behavior is more easily explained by thinking of light as a particle. In other situations, its behavior can only be explained if light i .....

.... the gas (water vapor) that makes up the bubbles you see in the boiling process. The standard temperature at which this occurs is 100 C or 212 F. In the very early stages of heating, you may see some small bubbles even though the water is only warm. This is some air that is dissolved in the cold water and is being expelled by the heating. This is not boiling. As the water nears the boiling point, some areas of the container close to the heat source may be hot enough to cause some boiling in that area which produces some local bubbles. To be sure that all of the water is .....

.... and deep infections called diabetic ulcers occur because of this. Pregnancy is affected by diabetes Mellitus. Many changes that take place during pregnancy make controlling blood sugar more difficult for a woman who has diabetes. Changes in the levels and types of hormones produced during pregnancy can cause insulin resistance, increasing the body’s requirements for insulin. Poorly controlled diabetes may endanger the fetus as well as the woman. With proper adjustments in insulin the risks lessen. Diabetes increases a pregnant woman’s risk of infection, early labor, and h .....

.... soreness, fever, bronchial complications, and even pneumonia. But while these conditions can be painful and frightening, we are usually confident that proper medication and rest will take care of the matter. However there is a much more severe and indiscriminate tyrant, with enormous corrupting influence, capable of infiltrating all of civilization. Scientifically, it is a submicroscopic pathogen consisting of a particle of nucleic acid, enclosed in proteins, and able to replicate only within a living cell. Socially, it is responsible for an enormous amount of chaos and f .....

.... (nightshades, jimson weed). It may have been this association with the nightshades which originally led people to believe the tomato to be poisionous. It was therefore fortunate that Miller changed the species name to esculentum which roughly means "edible". The common cultivated tomato belongs to the genus Lycopersicon. This genus exhibits a vast reservoir of genetic variability which remains largely underexploited. Some disease resistance, which is now a part of most commercially available cultivars, has been derived from related species of Lycopersicon. However, these othe .....

.... and endure as much physical pain as possible. The dance eventually gets so extreme that a young man in the crowd snaps his neck and dies. The man does not stop his ravings and the crowd doesn't stop their dance. Instead the man becomes entirely deranged, screaming at the body of the young man that he is now going to hell where he rot in flames of agony for eternity. The crowd roars and the man laughs. What do you suppose would now transpire? At the very least the man and the crowd would be arrested. More than likely there would be several charges of third degree murder l .....

.... networks used different protocols. A user could talk to others on their network, but not to someone on a different network. The protocol TCP/IP solves this problem. It is what allows a person on one network to communicate with a person on a different network. When I mentioned something to share in the network definition, it can be anything, an idea, document, or greeting. Networking allows use of applications on other computers, electronic mail (email), and real time discussions in chat rooms. The types of networks are classified as distributive or centralized. .....