They are called alkaline because they form solutions with a pH greater than 7, making them bases or "alkaline." Alkaline earth metals is a group of chemical elements in the periodic table with similar properties- shiny, silvery, somewhat reactive at standard temperature and pressure. They readily lose their two outermost electrons to form cations with charge +2.
Beryllium(Be):
Beryllium is a very rare metal that is almost never found in its pure form. It is part of the alkaline earth metals group which makeup the second column of the period table. Beryllium is a toxic bivalent element. primarily used as hardening agent in alloys. At standard temperature and pressures beryllium resist oxidation when expose to air.
Physical properties:
It is slate gray, strong, light-weight element.
Chemical properties:
Beryllium has one of the highest melting points of the light metals.
It has excellent thermal conductivity.
It is nonmagnetic.
It resists attack by concentrated nitric acid.
Occurrence:
Beryllium is most often found in the minerals beryl and bertrandite. It is found in the Earth's crust and mostly in igneous (volcanic) rocks. Most of the world's beryllium is mined and extracted in the United States and Russia.
Uses:
Beryllium is used as an alloying agent in the production of beryllium-copper. Due to their electrical and thermal conductivity, high strenght and hardness, non magnetic properties, good resistance, dimensional stability over a wide temperature range beryllium-copper alloys are used in many applications. A typical application of beryllium-copper alloys is in the defense and aerospace industries
It is used as a moderator and a shield in nuclear reactors.
beryllium Alloys with copper and nikel are used to make surgical instruments, precision instruments, and non-sparking tools that are used near flammable gases.
Beryllium is also used in the field of X-ray detection diagnostic (it is transparent to X-rays).
It is used in the making of various computer equipment.
Discovery:
In 1798 French chemist Louis Nicolas Vauquelin found Beryllium in the oxide form while doing an analysis of emerald and beryl and named it as "glucinum" . In 1828 the first pure beryllium was isolated by German chemist Friedrich Wohler. He didn't like the name "glucinum" for the element so he renamed it beryllium meaning "from the mineral beryl".
Fascinating facts:
In water, chemicals will react with beryllium, causing it to become insoluble. This is a good thing, because the water-insoluble form of beryllium can cause much less harm to organisms than the water-soluble form.
Beryllium has one of the highest melting points of the light metals. It has excellent thermal conductivity, is nonmagnetic.
Magnesium(Mg) :
Magnesium is very chemically active, it takes the place of hydrogen in boiling water and a great number of metals can be produced by thermionic reduction of its salts and oxidized forms with magnesium. It joins together with most non-metals and almost every acid. Magnesium reacts only slightly or not at all with most of the alkalies and many organic substances, like hydrocarbons, aldehydes, alcohols, phenol's, amines, esters and most of the oils.
Physical properties:
It is silver solid metallic element.
It is very light metal.
Magnesium burns with a very bright white light.
Chemical properties:
It is Used as a catalyst, magnesium promotes organic reactions of condensation, reduction, addition and dehalogenization.
It was used for a long time for synthesizing special and complex organic components by the well-known Grignard reaction.
It can form alloy with aluminum, manganese, zircon, zinc, rare-earth metals and thorium.
Occurrence:
Magnesium is fairly abundant on Earth in compounds and is found in over 60 different minerals in the Earth's crust. Some of the most important minerals include dolomite, magnesite, talc, and carnallite. The compound magnesium oxide (MgO) is the second most abundant compound in the Earth's crust making up around 35% of the crust by weight. Magnesium is also found dissolved in ocean water. In ocean water it takes the form of the cation Mg2+.
A lot of commercial magnesium used in the United States comes from a process using electrolysis to extract it from sea water.
Uses:
Magnesium compounds are used as refractory material in furnace linings for producing metals (iron and steel, nonferrous metals), glass, and cement.
Due to low density it is used in aeroplane and missile construction.
It also has many useful chemical and metallurgic properties, which make it appropriate for many other non-structural applications.
Magnesium components are widely used in industry and agriculture, in removal of sulphur form iron and steel, photoengraved plates in the printing industry.
It is used as reducing agent for the production of pure uranium and other metals from their salts.
It is used in flashlight photography, flares, and pyrotechnics.
Discovery:
It was first demonstrated by Scottish chemist Joseph Black in 1755 that the substance magnesia alba was a compound of different elements, one of them being magnesium. The element was first isolated by English chemist Sir Humphry Davy in 1808.
Magnesium gets its name from the district of Magnesia in Greece where the compound magnesium carbonate was first found.
Fascinating facts:
Magnesium is known for a long time as the lighter structural metal in the industry, due to it’s low weight and to it’s capability of forming mechanically resistant alloys.
It is used in flares and fireworks because of its bright white light when it burns.
Calcium(Ca):
Calcium is the third most abundant metal in the earth’s crust. The metal is harder than sodium, but softer than aluminium. A well as beryllium and aluminium, and unlike the alkaline metals, it doesn’t cause skin-burns. It is less chemically reactive than alkaline metals and than the other alkaline-earth metals.
Physical properties:
It is a silvery, shiny metal.
It is the lightest of all alkaline metals due to its low density.
Chemical properties:
When exposed to water, calcium will react and generate hydrogen.
When burned, it produces a bright orange-red flame.
Occurrence:
Calcium is rarely found in its elemental form, but is readily found throughout the Earth mostly in the form of rocks and minerals such as limestone (calcium carbonate), dolomite (calcium magnesium carbonate), and gypsum (calcium sulfate). It is the fifth most common element in the Earth's crust.
Calcium carbonate is one of the major components of many rocks and minerals including limestone, marble, calcite, and chalk. Calcium is also found in ocean water and is about the eighth most abundant element found in the ocean.
Uses:
Calcium compounds, rocks, and minerals such as limestone and marble are also used in construction.
Gypsum is used to make plaster of Paris and drywall.
It is used in the preparations of antacids, toothpaste, and fertilizer.
It is used in the productio of metals like chromium, thorium, zirconium and uranium.
It is used in removing pollution .
It is used in water purification.
Discovery:
It was discovered by English chemist Sir Humphry Davy in 1808.
Sir Humphry Davy named calcium after the Latin word "calx" which is means lime.
Fascinating facts:
A lack of calcium is one of the main causes of osteoporosis. Osteoporosis is a disease in which the bones become extremely porous, are subject to fracture, and heal slowly.
Calcium ions dissolved in water form deposits in pipes and boilers and when the water is hard, that is, when it contains too much calcium or magnesium. This can be avoided with the water softeners. In the industry, metallic calcium is separated from the melted calcium chloride by electrolysis.
Comments