Transition metals (1984)

Periodic table of Mendeleev.

Transition metals are elements located in the middle of the fourth, fifth and sixth periods of the periodic table.

All the atoms of these elements in the unexcited state have valence electrons at the s and d orbitals-sublevels.

Scandium is the first element with an electron in the d state.

After the s orbitals of the outer electron layer are populated, electrons in the d state appear in the atoms at the underlying level.

Their number does not increase monotonically as the sequence number increases.

As a consequence of the high stability of the half or completely filled d sublevels, chromium and copper atoms have a configuration with one electron in the s state.

In elements of periods 5 and 6, the settlement of d orbitals is even more non-monotonous.

In d element 6 of the lanthanum period, f orbitals are vacant.

Behind it are 14 elements of lanthanides.

Hafnium and the subsequent d elements of this period have four f orbitals filled.

The basic physical and chemical properties of elements are determined by the structure of their atom.

In the elements of the 4th period, electrons in the d state, having no similar ones in the atom, penetrate into the shell.

Due to inter-electronic interactions, the sizes of transition metal atoms decrease.

Electrons in 4 f orbitals compress the electron shell of atoms even more than in 3 d.

Despite the significant differences in the ordinal numbers, the atomic radii d of elements of 5 and 6 periods are close.

Therefore, the properties of these metals in groups are very similar and differ from the properties of elements of the 4th period.

Transition metals under normal conditions have either a volume-centered cubic, or a face-centered cubic, or a hexagonal lattice of dense packing.

Samples of minerals.

The compactness of the crystal lattices of d elements determines the high density of their solids.

Samples of transition metals in nature.

Cartoon about the spread of transition metals in the Earth's crust.

An open mine for the extraction of transition metals in the form of ore.

In the blast furnace process of obtaining transition metals, solid carbon and carbon monoxide serve as reducing agents.

When melting cast iron in a blast furnace, iron carbide - cementite is formed.

The essence of the steelmaking process is to reduce

carbon content and oxidation of impurities in cast iron.

Iron is a polymorphic metal at high temperatures gamma-iron or austenite is stable, and at low temperatures alpha-iron or ferrite.

As a result of slow cooling, austenite turns into soft steel perlite.

Active metals, such as aluminum, restore the compounds of d elements.

Alumothermy is used in the production of chromium, vanadium.

The workshop of the plant, metal ingots are stacked on the floor.

Electrolysis of aqueous solutions or melts of salts and oxides is used to isolate and purify some transition metals.

The physical and mechanical properties of metals largely depend on the degree of their purification.

Metals of high purity are obtained by melting in vacuum.

Samples of pure metal.

As a result of remelting in vacuum, dissolved gases are removed, and as a result of zone melting, solid impurities are also removed.

All d elements are reducing agents.

Many of them are able to displace hydrogen from acidic aqueous solutions.

Most of the d elements in the air are covered with a protective film that prevents oxidation processes.

Copper and metals of the 8th group of the 5th and 6th periods are dissolved only in nitric acid or aqua regia.

Table of the degree of oxidation of metals.

Experiments on the effect on divant manganese.

Potassium permanganate.

Experiments with permanganates.

Experiments with chromium.

Experiments with vanadium compounds.

Table of the dependence of the heats of the formation of oxides on the ordinal number.

Graph of the dependence of the heats of the formation of oxides on the ordinal number.

Transition metal oxides are compounds of variable composition.

The presence of vacant positions in their structure determines the existence of a wide area of homogeneity, for example, in titanium oxides.

Within the titanium-oxygen system, a wide range of physical properties of compounds is observed.

Samples of transition metal oxides and paints based on them.

The porthole of the spacecraft is made of transition metal oxides.

Transition metal oxides are used in leather production, photography and pyrotechnics.

Experiments on the preparation and effect on transition metal hydroxides.

Despite the dense packing, there are voids in the lattices between the transition metal atoms, which can embed atoms of light elements.

Tables of melting points of metals and their carbides.

A graph of the dependence of the melting temperature of metals and their carbides on the ordinal number.

A machine with cutters made of tungsten and titanium carbides.

Experience with pure iron.

Properties of alloy steel.

Additives to refractory metals.

Protection of molybdenum.

Samples of halides.

A cartoon explaining gas-phase metallurgy.

Halides of molybdenum, niobium and other d elements form clusters - large molecules in which metal atoms are interconnected.

Silver halides are used for the development of film.

An important feature of populated and vacant d orbitals of transition metal ion atoms is their ability to create compounds.

The number of these compounds is large and diverse.

Experiments on the production of complex compounds.

A line for the deposition of copper, silver and gold on metal surfaces.

Painting of machine parts.

Microchips.

Assembly of microchips.

Installations for the synthesis of various compounds.

Ammonia oxidation device.

Panorama of a chemical plant.