Nursing Preparation Study Guide

Nursing Preparation Study Guide of 173 primary types of solids, each defined by the structures in which their molecules are held. When the molecules in solidmatter maintain a uniformorganization, they form a polycrystalline structure. This is howmolecules in metal, ice, and salt are organized. Polycrystalline structures are generally a result of the molecules’ ionic properties. Water molecules, for instance, are formed in such a way that there are distinct ends – one with two hydrogen atoms and one with a single oxygen atom. The structure of the atoms within a water molecule means these ends are charged, giving it poles and causing water molecules to join only in specific patterns. Under a microscope, polycrystalline solids are described as resembling lattice work or a chain link fence, with the same pattern of molecules from one end to the other. When molecule’s electromagnetic properties do not incline them to form into particular structures, they glob together in any patterns possible. This produces amorphous solids, most notably foams, glass, andmany types of plastic. Amorphous solids have no regular pattern throughout their structure and, as a result, are poor conductors of heat and electricity. Liquid When solids are heated past a certain point, the electromagnetic bonds holding their molecules together loosen, and the molecules are able to move more freely. While the temperatures required for this to happen can vary widely, the physical qualities of liquids always remain constant. Liquids are considered to be fluids, which differ from solids primarily in their ability to take the shape of any container in which they are held. This is the result of a less intense electromagnetic connection between the molecules than there is in solids; however, there is still enough of that liquid that wants to stay all in the same place. This is why liquids still maintain a low density that is nearly identical to their densities in solid form. It is also why liquids will maintain a constant volume rather than just drift off the way gasses do. 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 ©2018 Achieve Test Prep Page 161

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