Alkaline earth metals areelements that belong to the second group of the periodic table. This could include substances such as calcium, magnesium, barium, beryllium, strontium, and radium. The name of this group indicates that they give an alkaline reaction in water.
Alkali and alkaline earth metals, or rather their salts, are widely distributed in nature. They are represented by minerals. The exception is radium, which is considered a rather rare element.
All of the above metals have some common qualities that made it possible to combine them into one group.
Alkaline earth metals and their physical properties
Практически все эти элементы представляют собой grayish solids (at least under normal conditions and room temperature). By the way, the physical properties of alkali metals are slightly different - although these substances are rather stable, they are easily affected.
Interestingly, with a sequence number in the tablesuch an indicator of metal as density is growing. For example, in this group, calcium is the lowest, while radium is similar in density to iron.
Alkaline earth metals: chemical properties
For a start it is worth noting that the chemicalactivity increases according to the sequence number of the periodic table. For example, beryllium is a fairly resistant element. It reacts with oxygen and halogens only with strong heating. The same goes for magnesium. But calcium is able to slowly oxidize at room temperature. The other three members of the group (radium, barium and strontium) react quickly with oxygen in the air at room temperature. That is why they store these elements, covering with a layer of kerosene.
The activity of oxides and hydroxides of these metalsincreases in the same way. For example, beryllium hydroxide does not dissolve in water and is considered an amphoteric substance, and barium hydroxide is considered to be a fairly strong alkali.
Alkaline earth metals and their brief description
Beryllium is a resistant metal.light gray color with high toxicity. The element was first discovered in 1798 by the chemist Voklen. In nature, there are several beryllium minerals, of which the following are considered the most famous: beryl, phenacite, danalite, and chrysoberyl. By the way, some isotopes of beryllium are highly radioactive.
Interestingly, some forms of beryl are valuable gemstones. These include emerald, aquamarine and heliodor.
Beryllium is used for the manufacture of some alloys, rocket fuel. In nuclear power, this element is used to slow down neutrons.
Кальций является одним из самых известных alkaline earth metals. In its pure form, it is a soft white substance with a silvery shade. For the first time, pure calcium was isolated in 1808. In nature, this element is present in the form of minerals such as marble, limestone and gypsum. Calcium is widely used in modern technology. It is used as a chemical source of fuel, as well as a fire-resistant material. It's no secret that calcium compounds are used in the manufacture of building materials and medicines.
This element is also found in every living organism. Basically, he is responsible for the operation of the motor apparatus.
Magnesium is light and sufficientDuctile metal with a characteristic grayish color. In its pure form, it was isolated in 1808, but its salts became known much earlier. Under natural conditions, magnesium is found in such minerals as magnesite, dolomite, carnallite, and kieserite. By the way, magnesium salt provides water hardness. A huge amount of compounds of this substance can be found in sea water.
