Classes of simple substances
The principle of separation of simple substances is by electronic shell. Depending on the electronic configuration, the atoms they exhibit different properties in compounds, the classification of simple chemicals according to IUPAC is given below.
| Name | Elements | Being in the periodic table |
|---|---|---|
| Alkali metals (alkali metals) | Li, Na, K, Rb, Cs, Fr | The first group |
| Alkaline earth metals (alkaline earth metals) | Be, Mg, Ca, Sr, Ba, Ra | The second group |
| Nitrogen subgroup (pnictogens) | N, P, As, Sb, Bi | 15th group |
| Chalcogens (chalcogens) | O, S, Se, Te, Po | group 16 |
| Halogens (halogens) | F, Cl, Br, I, At | 17th group |
| Noble gases (noble gases) | He, Ne, Ar, Kr, Xe, Rn | 18th group |
| Lanthanoids (lanthanoids) | La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu | Group III of the sixth period |
| Rare earth metals (rare earth metals) | Sc, Y and lanthanides | |
| Actinoids (actinoids) | Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr | Group III of the seventh period |
| Table 1. Chemical elements of simple substances. Separation of simple substances by IUPAC | ||
Alkali metals
All alkali metals have one electron at the external energy level, therefore, as a rule, alkali metals in compounds they are represented by cations with an oxidation state of "+1". Alkali metals have a silvery-white color, except caesium, caesium has a silvery-yellow color. All alkali metals are soft, they can be cut with a scalpel. During gorenje, atoms are ionized and they paint the flame in different colors.
Alkali metals are most often obtained by electrolysis of natural minerals represented by halides (fluoride, chloride, bromide, iodide), for example from Sylvin (KCl).
Alkaline earth metals
Alkaline earth metals are gray in color, solid at room temperature. At the external energy level , there are two electrons, therefore, they are easily given away and in compounds have an oxidation state of "+2", less often - "+1". Alkaline earth metals they have a high activity, therefore they are found in nature only in compounds.
Alkaline earth metals, as a rule, are obtained by electrolysis of minerals, for example, brucite (Mg(OH)2).
Nitrogen subgroup
The electronic configuration of the elements of the nitrogen subgroup at the external energy level has five electrons, ns2np3. In compounds, elements from the nitrogen subgroup have an oxidation state from "-3" to "+5".
The hydrogen compounds of the elements correspond to the formula RN3: NN3 – ammonia, PH3 – phosphine, AsN3 – arsin, SbN3 – stibin, ViN3 – bismuthin. All compounds are gases, chemical resistance of each it weakens, which is associated with an increase in the ordinal number of elements, weakening of non-metallic properties and strengthening of metallic ones.
Chalcogens
The term "chalcogen" comes from the Greek words "chalkos" - copper and "genos" - born, since chalcogens are most often in nature they are found in compounds with copper. One of the characteristic properties of chalcogen atoms is their ability to bind to each other in rings or chains due to the different strength of single and double bonds.
Halogens
Halogens are strong oxidizing agents, therefore they occur in nature in the form of compounds, with an increase in the sequence number of chemical the activity of halogens decreases. There are seven electrons on the outer shell, and the atom attaches one electron to complete the shell. In some compounds, they have positive oxidation states.
Noble gases
Noble gases have a full electron shell, so they do not react under normal conditions. Noble gases are colorless and they have no smell.
Lanthanides
All Lanthanides, with the exception of La and Lu, have strong paramagnetism at temperatures above room temperature, the cause of which is the presence of these elements have spin and orbital magnetic moments uncompensated in 4f subshells.
Actinoids
Actinoids include radioactive elements.
