The basic laws of change of magnetic properties of elementary substances in Periodic system of elements

P.S. Kirey¹

 ¹ EU, European University, P.O.Box 562, Nikolaev 54031, Ukraine

 E-mail: kpskps@km.ru

 

On a sign molar magnetic susceptibility χ_m elementary substances can be classified as follows:

1.     Paramagnetics (χ_m > 0, switching ferro-and antiferromagnetics) – 51 elements;

2.     Diamagnetics (χ_m < 0) – 31 elements;

3.     Magnetic amphoteric elements (elements at which different allotropic and polymorphic updatings have different signs χ_m at room temperature and normal atmospheric pressure) - 3 elements (carbon, oxygen, tin).

4.     Magnetic unidentified elements (elementary substances, at which size and sign χ_m are unknown owing to their high chemical or radiating activity, very small size of a half-life period or synthesized in very small quantities) - 25 elements.

The fluorine, four elements of 6-th period (promethium, polonium, astatine and radon) and the majority of elements of 7-th period (the size χ_m is known only for 4 elements-actinoids: thorium, uranium, plutonium and americium) concern to the Magnetic unidentified elements. If to start with the general physical representations and measurements of the magnetic moments of ions in connections fluorine, polonium, astatine and radon it is necessary to attribute to diamagnetics, and promethium - to paramagnetics.

Diamagnetic elements prevail in the short periods of periodic system, and paramagnetic - in long. Distribution dia-and paramagnetics in the long periods completely identically: all periods contain identical quantity of diamagnetic elements (N_d = 8) in the ending of each period, and the quantity of paramagnetic elements in the beginning of each period makes N_p = N - N_d, where N - the general number of elements in the period.

The quantitative analysis of laws of change of size χ_m in Periodic system shows, that, since 4-th period, periodicity of change of magnetic properties of elementary substances on the periods of the table of D.I. Mendeleyev [1, 2] is observed. Thus magnetic properties lanthanoids and actinoids have the individual features and do not submit to periodic law. Magnetic ordered substances (chromium, manganese, iron, cobalt, nickel) also drop out of the general laws.

The quantitative analysis of change of size χ_m in Periodic system is at a loss that circumstance, that the data on size χ_m, resulted in different sources [3 - 7], contradict each other and in some cases differ on orders. For reception of authentic values of size χ_m its averaging on the values resulted in different sources was carried out, thus those values which in some times differed from similar sizes from other sources were rejected.

The basic tendency of change of size χ_m from atomic number Z within the limits of groups its monotonous decrease close to linear (for groups 3 - 12, 16 - 18) is, and for groups 1, 2, 13 - 15 given dependence has more complex character. Linear character of function χ_m = f(Z) for groups 3 - 12, 16 - 18 gives the basis for extrapolation of the given dependences in transbismuth area and to interpolation in case of fluorine. Function χ_m = f (Z) for actinoids also with a high degree of accuracy it is approximated by linear dependence that allows to receive unknown values χ_m for protactinium and neptunium a method of interpolation.

In the table results of linear approximation of dependence χ_m are submitted from atomic number Z (χ_m = К₁Z + К₂) on groups of Periodic system. Number of group is specified in 1-st column for the developed Periodic system; in 2-nd – quantity of known values χ_m (points) within the limits of the given group; in 3-rd and 4-th - factors of approximating dependence; in 5-th - size of reliability of approximation; in 6-th - the name of an element of the given group, for which value χ_m it is defined (determined) by a method of extrapolation or interpolation; in 7-th - atomic number of the element specified in 6-th column; in 8-th - size χ_m for an element specified in 6-th column.

 The Table. Results of linear approximation of dependence χ_m from atomic number Z on groups of Periodic system of elements of D.I.Mendeleyev.

* - value |χ_m| for the given element close to value |χ_m| for bismuth.

** - value |χ_m| for the given element exceeds value |χ_m| for bismuth. 

As for elements 6 - 10 groups approximating dependences have been constructed all on two points (without taking into account magnetic ordered substances) the results received for them in many respects can be considered as hypothetical. Among the given elements there are two elements (with atomic numbers 157 and 160), at which value |χ_m| considerably exceeds value |χ_m| for bismuth, which now is record for diamagnetic elementary substances. At two elements (with atomic numbers 121 and 167) values |χ_m| are close to value |χ_m| for bismuth.

The analysis of the received results shows, that in 7-th and 8-th periods the law observable in 4 - 6 periods according to which elements 3 - 10 groups are paramagnetics is broken. In 7-th period actinium, bohrium, hassium, meitnerium and darmstadtium possess diamagnetic properties, and in 8-th period all elements 3 - 10 groups are diamagnetics. Thus, in 7-th and 8-th periods "washing out of periodicity" magnetic properties of elementary substances should be observed. The given conclusion logically supplements a hypothesis about "washing out of periodicity" physical and chemical properties of the elements, put forward in work [8]. And, as well as in work [8], transitive elements at transition from areas of a periodic table with well defined periodicity to areas with dim periodicity, are actinium and an element with Z = 121. 

Literature: 

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2.     P.S. Kirey. The learning of the magnetic properties of the elementary substances in technical University // The 3^th International Industrial Conference «The effectiveness of the realization of the scientific, resource and industrial potential in the modern conditions»: Book of papers. – Кiev, 2003. – P. 129 – 131.

3.     J. Emsley. The Elements. – М.: Мir, 1993.

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5.     The Tables of the physical magnitude: Handbook. Common edition – I.K. Kikoin. – М.: Аtомizdat, 1976.

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8.     D.N. Тrifonov. Heavy elements and Periodic system // Periodic law and structure of the atom: Book of papers. – М.: Аtомizdat, 1971. – P. 204 – 238.