Characteristics of Alkaline Earth Metals
The alkaline earth metals are a group of elements on the periodic table that are highly reactive and share common traits. These metals, which are found in common compounds like marble and chalk, have a variety of industrial applications. Some of these elements are essential to life, and some are toxic, but all of them have important uses in modern manufacturing processes.
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Elements
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Group 2 of the periodic table of the elements is comprised of the alkaline earth metals. These metals include beryllium, magnesium, calcium, strontium, barium and radium. They are closely related to the alkali metals and share common properties with them. All group 2 elements are metals.
Common Properties
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The alkaline earth elements have an oxidation number of +2. This means they are very reactive and tend to form strong chemical bonds with other atoms, so they are not generally found in a pure state in nature. These metals tend to be white or silvery, shiny, and very soft, and have a very high melting point. These metals tend to react strongly with water and various acids to produce hydrogen. They also form strong bonds with oxygen.
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Industrial Uses
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Various alloys of the alkaline earth metals have critical industrial uses. Magnesium alloys are often used in high-temperature applications, including lightweight engine parts. Calcium is used in the making of steel and substances such as gypsum. Strontium is a common component in flares and pyrotechnics because it burns with a bright crimson flame; barium is used similarly except its characteristic color is green.
Magnesium has a brilliant white flame when burning, making it a common ingredient in flares, tracer bullets and similar applications.
Health Implications
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Magnesium and calcium are critical to life; they play a role in the ion pumps that regulate cell behavior, and magnesium is the central atom in the chlorophyll molecule. Other elements, including radium and beryllium, have no biological value and as such are toxic to most organisms, including humans. Strontium is critical for marine life; it is an ingredient in coral. Although barium has no real biological function, it is used to prepare a "barium meal" that, when consumed by a patient, permits greater detail in certain radiology scans. Barium in large doses, and radium, are radioactive and as such can be lethal in high doses.
Naturally Occurring Compounds
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Although the alkaline earth metals generally do not appear in pure form in nature, they form compounds that are abundant in nature. For example, limestone, marble, chalk, dolomite, mica and asbestos are all based on an alkaline earth metal. These minerals have been used in industry and architecture for centuries and form a significant source of the raw materials broken down to isolate the pure metals.
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References
Resources
- Photo Credit denn: flickr.com