Metals are the most important and in many waysunique chemical elements. Virtually all of them are characterized by such properties as good electrical conductivity, gloss, thermal conductivity. At the same time, among them one can distinguish separate groups whose characteristics will differ substantially. A part of these distinctive features formed the basis of such a concept as "a series of metal activity".
The conditionality of the place of each element in a given rowfollows from the fact that at different temperatures and composition of the solution they behave more or less actively. The average values of the indicators are derived at a solution temperature of 25 degrees Celsius and gas pressure in one atmosphere. It is under such conditions that a number of metal activities take the form that is familiar to each of the school chemistry courses.
Of all these indicators, a whole listmost important properties. First, a number of tensions in metals can help us predict how certain elements behave during the reaction: those that are in the given sequence to the left will replace those that are to the right of them. Secondly, if the element is located to the left of hydrogen, the electrode potential of which is assumed to be equal to zero, then it can displace it from acid solutions. This applies in particular to lithium, sodium, potassium and other alkaline elements. Finally, thirdly, a number of metal activities are of considerable help in the creation of galvanic cells: the farther apart the elements are in it, the higher the electric potential between them will arise.
It is curious to compare certainThe regularities that follow from the Periodic Table and the given sequence. So, based on the work of Mendeleev, potassium should be more active than the sodium and lithium, but a number of tension gives a very different picture. The main reason for this contradiction lies in the grounds that form the basis of these sequences. Periodic system reflects the change in the value of the ionization energy of the atoms, and Beketova sequence - the kind of work to be done to put one or other element of the solid state into a plurality of ions in an aqueous solution idea.