n element in the same physical state. Oxygen is an allotrope, ozone and diatomic oxygen are allotropes of oxygen. Allotropes may have properties that vary widely, diatomic oxygen is colorless, odorless, and essential to life, whereas ozone is blue, toxic, and have a very sharp odor. Compounds- Compounds are pure substances composed of two or more different elements. - Molecular compounds are composed of molecules. Ionic compounds such as table salt, are made of at least 2 different elements that are chemically joined, but the atoms are not made of discrete molecules but instead are distributed throughout a continuous network. - Compounds have unique sets of properties, these properties may vary greatly from those of the elements used to create them. - There are 3 major differences between compounds and mixtures. 1. Mixtures are never made of only a single compound.2. A mixtures properties reflect the substances used to create it, whereas a compound often bears no resemblance to the properties of the elements used to make it.3. Compounds have a definite composition by mass of their combining elements. Pyrite for example always exists with a mass of 46.55% iron 53.45% sulfur. While substances exist in any mass ratio.Methods of separating mixtures- Filtering, evaporating, centrifuging, or decanting a mixture brings about only physical changes. The substances gained from these processes are not chemically changed. - Chromatography can be used to separate the components of a solution so they may be identified. It works because different substances are attracted to different solvents and other media. - Distillation is a method of separating substances that have different boiling points- In some spots around the world, people use distillation to obtain drinking water from sea water. But this process requires much energy and is very expensive, so other ways of getting drinking water are preferred. Distillation is used in the petro...
