physical properties of alkali metals
All the alkali metals other than cesium, have a pronounced metallic sheen and silvery shade.Cesium has a golden hue.All are in the solid state are obemotsentrirovannuyu cubic lattice with two atoms per cell.Link type of atoms - the metal.This leads to their high electrical conductivity.Alkali metals (other than lithium) can be easily cut with a knife.At room temperature, they are almost pasty.
piece of cesium can be melted by simply holding it in your hand.The melting point of the metal is only 29oS.The lower sequence number in the Periodic Table, the higher the temperature.The density of alkali metals is very low.Lithium, the most dense of them floating in kerosene.Sodium and potassium are able to swim in water.
chemical properties of alkali metals
Alkali metals are characterized by high chemical activity.Atom
s of these elements is very low values of the ionization potentials.In order to detach an electron from the s-shell (ionized atoms), need relatively little energy.
Optical spectra of alkali metals possess the bright lines of all elements of the periodic table.The low value of the ionization potential makes it easy to get help with their characteristic light emission and record his spectroscope.Couples cesium paint flames in the blue-green color, sodium vapor - in bright yellow.
Alkali metals are stored in special vials under a layer of kerosene.Even the air in the surface layer of the metal oxide film is formed.It appears on lithium nitride.Nitrides other similar metals are formed.Alkaline
these metals are called for their ability to form alkali upon contact with water.This caustic substances that damage human skin and any fabric.None of the alkali metals should not be handled without gloves.Upon contact with the skin, they form an alkali.Before working with them need to study safety.
These metals react with dilute acids.The occurrence of such a reaction is not always possible to predict, since hydrogen and alkali, which then neutralize the acid.Typically the reaction with an acid followed by the explosion, however in practice they are not performed.
All alkali metals are inherently reducing agents.They are able to recover the less active metals from their compounds.Thus it is possible to obtain it from aluminum chloride.
- Alkali metals