Nursing Entrance Exam

Liquids also have a property known as viscosity, which describes their willingness to flow over and away from themselves. Liquids like water and honey have constant viscosity and are known as Newtonian fluids. Non-Newtonian fluids, such as a goopy mixture of water and cornstarch, can change their viscosities. Gas The third state of matter commonly found on Earth is gas. Gasses are formed when matter is heated beyond its liquid state so that the electromagnetic bonds holding its molecules together are almost completely severed. Gasses are viewed as fluids and, like liquids, have no definite shape. However, they lack a definite volume and have an extremely low density compared to their solid forms, which differs from liquids. Since gasses lack both a shape and a volume, they will expand to fill any container in which they are placed. Left unbounded, they will expand forever. Conversely, gasses are perfectly happy to compress in an enclosed space. However, the more molecules of a gas that are enclosed in a space together, the higher the gas’s pressure, which is the force exerted on the container’s surface by the molecules. An interesting fact about expansion and compression is that it will always be homogeneous, meaning that as a gas expands to fill a container, there will never be pockets of higher density of molecules in some areas with a lower density of molecules in others. Themolecules will expand to fill the container equally. Plasma Plasma is the next step up from a gas; it is when a gas’s molecules become super-heated – to the point at which molecular bonds break down and the atoms begin shedding their electrons. Although plasma is rarely found on Earth, it is the most common state of matter throughout the universe. It is the primary state of matter in stars, for instance. Plasma has some unique characteristics, not the least of which is that it is ionized, or electrically charged. In many ways, plasma acts like a gas. It lacks any definite shape or volume, and will homogeneously fill any container. It can also be manipulated by electromagnetic fields, which alter its shape or contain it. Plasma is a super-heated, magnetically charged gas. Evaporation, Vaporization, and Condensation Evaporation Evaporation is a vaporization process that occurs only on liquid surfaces. It is a process whereby liquid is converted to gas by the application of heat energy.

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