General information:
| 100 | General information | |
| 101 | Name | Aluminum |
| 102 | Former name | |
| 103 | Latin name | Aluminum |
| 104 | English name | Aluminum, Aluminum (in the USA and Canada) |
| 105 | Symbol | Al |
| 106 | Atomic number (number in table) | 13 |
| 107 | Type | Metal |
| 108 | Group | Amphoteric, light, non-ferrous metal |
| 109 | Open | Hans Christian Ørsted, Denmark, 1825 |
| 110 | Opening year | 1825 |
| 111 | Appearance, etc. | Soft, light and ductile silver-white metal |
| 112 | Origin | Natural material |
| 113 | Modifications | |
| 114 | Allotropic modifications | |
| 115 | Temperature and other conditions for the transition of allotropic modifications into each other | |
| 116 | Bose-Einstein condensate | |
| 117 | 2D materials | |
| 118 | Content in the atmosphere and air (by mass) | 0 % |
| 119 | Content in the earth's crust (by mass) | 8,1 % |
| 120 | Content in seas and oceans (by mass) | 5,0·10-7 % |
| 121 | Content in the Universe and space (by mass) | 0,005 % |
| 122 | Abundance in the Sun (by mass) | 0,006 % |
| 123 | Content in meteorites (by mass) | 0,91 % |
| 124 | Content in the human body (by weight) | 0,00009 % |
Comparison of the properties of substances with different crystal lattices
The type of crystal lattice (or lack of a crystal lattice) allows one to evaluate the basic physical properties of a substance . To roughly compare the typical physical properties of compounds with different crystal lattices, it is very convenient to use chemicals with characteristic properties. For a molecular lattice this is, for example, carbon dioxide, for an atomic crystal lattice - diamond, for a metal lattice - copper, and for an ionic crystal lattice - table salt, sodium chloride NaCl.
Summary table on the structures of simple substances formed by chemical elements from the main subgroups of the periodic table (elements of the side subgroups are metals, therefore, have a metallic crystal lattice).
The final table of the relationship between the properties of substances and their structure:
Properties of the aluminum atom:
| 200 | Properties of the atom | |
| 201 | Atomic mass ( molar mass ) | 26.9815386(8) amu (g/mol) |
| 202 | Electronic configuration | 1s2 2s2 2p6 3s2 3p1 |
| 203 | Electronic shell | K2 L8 M3 N0 O0 P0 Q0 R0 |
| 204 | Atomic radius (calculated) | 118 pm |
| 205 | Empirical atomic radius* | 125 pm |
| 206 | Covalent radius* | 121 pm |
| 207 | Ion radius (crystalline) | Al3+ 53 (4) pm, 67.5 (6) pm (in parentheses the coordination number is indicated - a characteristic that determines the number of nearest particles (ions or atoms) in a molecule or crystal) |
| 208 | Van der Waals radius | 184 pm |
| 209 | Electrons, Protons, Neutrons | 13 electrons, 13 protons, 14 neutrons |
| 210 | Family (block) | p-family element |
| 211 | Period in the periodic table | 3 |
| 212 | Group on the periodic table | 13th group (according to the old classification - the main subgroup of the 3rd group) |
| 213 | Emission spectrum |
Metal crystal lattice
And finally, metals are characterized by a special type of spatial structure - a metal crystal lattice , which is caused by a metallic chemical bond . Metal atoms hold valence electrons rather weakly. In a crystal formed by a metal, the following processes occur simultaneously: some of the atoms give up electrons and become positively charged ions; these electrons move randomly in the crystal; Some electrons are attracted to the ions. These processes occur simultaneously and chaotically. Thus, ions are created , as in the formation of an ionic bond, and shared electrons are formed , as in the formation of a covalent bond. Free electrons move randomly and continuously throughout the entire volume of the crystal, like a gas. Therefore, they are sometimes called " electron gas ". Due to the presence of a large number of mobile charged particles, metals conduct current and heat . The melting point of metals varies greatly. Metals are also characterized by a peculiar metallic luster, malleability , i.e. the ability to change shape without destruction under strong mechanical stress, because chemical bonds are not destroyed.
Bonding between particles : metallic chemical bonding.
Metal ions and atoms at the nodes of a crystal with a metal lattice .
Phase state of metals under normal conditions: usually solids (with the exception of mercury, liquid under normal conditions).
Chemical substances with a metal crystal lattice are simple metal substances .
Physical properties of substances with a metal crystal lattice:
— high thermal and electrical conductivity;
— malleability and plasticity;
- metallic luster;
- metals are usually insoluble in solvents;
- Most metals are solids under normal conditions.
Chemical properties of aluminum:
| 300 | Chemical properties | |
| 301 | Oxidation states | 0, +1, +2, +3 |
| 302 | Valence | III |
| 303 | Electronegativity | 1.61 (Pauling scale) |
| 304 | Ionization energy (first electron) | 577.54 kJ/mol (5.985769(3) eV) |
| 305 | Electrode potential | Al3+ + 3e— → Al, Eo = -1.663 V |
| 306 | Electron affinity energy of an atom | 41.762(5) kJ/mol (0.43283(5) eV) |
Properties and characteristics
Aluminum is a metal with a silvery-white surface. As already noted, its density is 2.7 kg/m3. The temperature is 660°C.
Its electrical conductivity is equal to 65% of copper and its alloys. Aluminum and most of its alloys are resistant to corrosion. This is due to the fact that an oxide film forms on its surface, which protects the base material from exposure to atmospheric air.
In the untreated state, its strength is 60 MPa, but after adding certain additives it increases to 700 MPa. The hardness in this state reaches 250 HB.
Aluminum can be easily processed under pressure. To remove work hardening and restore ductility after processing, aluminum parts are annealed, and the temperature should be within 350°C.
Physical properties of aluminum:
| 400 | Physical properties | |
| 401 | Density* | 2.70 g/cm3 (at 20 °C and other standard conditions, state of matter – solid), 2.375 g/cm3 (at a melting point of 660.32 °C and other standard conditions, the state of matter is liquid), 2.289 g/cm3 (at 1000 °C and other standard conditions , state of matter - liquid) |
| 402 | Melting temperature* | 660.32 °C (933.47 K, 1220.58 °F) |
| 403 | Boiling temperature* | 2470 °C (2743 K, 4478 °F) |
| 404 | Sublimation temperature | |
| 405 | Decomposition temperature | |
| 406 | Self-ignition temperature of a gas-air mixture | |
| 407 | Specific heat of fusion (enthalpy of fusion ΔHpl)* | 10.71 kJ/mol |
| 408 | Specific heat of evaporation (enthalpy of boiling ΔHboiling)* | 284 kJ/mol |
| 409 | Specific heat capacity at constant pressure | 0.903 J/g K (at 25 °C) |
| 410 | Molar heat capacity* | 24.20 J/(K mol) |
| 411 | Molar volume | 9.993 cm³/mol |
| 412 | Thermal conductivity | 237 W/(mK) (at standard conditions), 237 W/(mK) (at 300 K) |
| 413 | Thermal expansion coefficient | 23.1 µm/(MK) (at 25 °C) |
| 414 | Thermal diffusivity coefficient | |
| 415 | Critical temperature | |
| 416 | Critical pressure | |
| 417 | Critical Density | |
| 418 | Triple point | |
| 419 | Vapor pressure (mmHg) | |
| 420 | Vapor pressure (Pa) | |
| 421 | Standard enthalpy of formation ΔH | |
| 422 | Standard Gibbs energy of formation ΔG | |
| 423 | Standard entropy of matter S | |
| 424 | Standard molar heat capacity Cp | |
| 425 | Enthalpy of dissociation ΔHdiss | |
| 426 | The dielectric constant | |
| 427 | Magnetic type | |
| 428 | Curie point | |
| 429 | Volume magnetic susceptibility | |
| 430 | Specific magnetic susceptibility | |
| 431 | Molar magnetic susceptibility | |
| 432 | Electric type | |
| 433 | Electrical conductivity in the solid phase | |
| 434 | Electrical resistivity | |
| 435 | Superconductivity at temperature | |
| 436 | Critical magnetic field of superconductivity destruction | |
| 437 | Prohibited area | |
| 438 | Charge carrier concentration | |
| 439 | Mohs hardness | |
| 440 | Brinell hardness | |
| 441 | Vickers hardness | |
| 442 | Sound speed | |
| 443 | Surface tension | |
| 444 | Dynamic viscosity of gases and liquids | |
| 445 | Explosive concentrations of gas-air mixture, % volume | |
| 446 | Explosive concentrations of a mixture of gas and oxygen, % volume | |
| 446 | Ultimate tensile strength | |
| 447 | Yield strength | |
| 448 | Elongation limit | |
| 449 | Young's modulus | |
| 450 | Shear modulus | |
| 451 | Bulk modulus of elasticity | |
| 452 | Poisson's ratio | |
| 453 | Refractive index |
Atomic crystal lattice
An atomic crystal lattice is formed when atoms . The atoms are connected to each other by strong covalent chemical bonds . Accordingly, such a crystal lattice will be very strong and not easy to destroy. An atomic crystal lattice can be formed by atoms with high valency, i.e. with a large number of bonds with neighboring atoms (4 or more). As a rule, these are non-metals: simple substances - silicon, boron, carbon (allotropic modifications diamond, graphite), and their compounds (borocarbon, silicon oxide (IV), etc.). Since a predominantly covalent chemical bond occurs between nonmetals, in most cases there are no free electrons (as well as other charged particles) in substances with an atomic crystal lattice . Consequently, such substances, as a rule, conduct electricity very poorly, i.e. are dielectrics . These are general patterns, to which there are a number of exceptions.
Bonding between particles in atomic crystals: covalent polar or nonpolar .
Atoms at the nodes of a crystal with an atomic crystal structure .
Phase state of atomic crystals under normal conditions: usually solids .
Substances that form atomic crystals in the solid state:
- Simple substances with high valency (located in the middle of the periodic table): boron, carbon, silicon, etc.
- Complex substances formed by these non-metals: silica (silicon oxide, quartz sand) SiO2; silicon carbide (carborundum) SiC; boron carbide, boron nitride, etc.
Physical properties of substances with an atomic crystal lattice:
- strength;
— refractoriness (high melting point);
— low electrical conductivity;
— low thermal conductivity;
— chemical inertness (inactive substances);
- insolubility in solvents.
Aluminum crystal lattice:
| 500 | Crystal cell | |
| 511 | Crystal grid #1 | |
| 512 | Lattice structure | Cubic face centered |
| 513 | Lattice parameters | 4.050 Å |
| 514 | c/a ratio | |
| 515 | Debye temperature | 394 K |
| 516 | Name of space symmetry group | Fm_3m |
| 517 | Symmetry space group number | 225 |
Melting point of aluminum
The production of aluminum melt, like many other materials, occurs after thermal energy has been supplied to the original metal. It can be supplied either directly into it or from outside.
The melting point of aluminum directly depends on the level of its purity:
- Ultra-pure aluminum melts at a temperature of 660.3°C.
- With an aluminum content of 99.5%, the melting point is 657°C.
- With a content of this metal of 99%, the melt can be obtained at 643°C.
Aluminum melt
Aluminum production process
An aluminum alloy can contain various substances, including alloying ones. Their presence leads to a decrease in the melting point. For example, if there is a large amount of silicon, the temperature can drop to 500°C. In fact, the concept of melting point applies to pure metals. Alloys do not have any constant melting point. This process occurs within a certain heating range.
In materials science there is a concept - solidus and liquidus temperatures.
The first temperature indicates the point at which the melting of aluminum begins, and the second shows at what temperature the alloy will finally melt. In the interval between them, the alloy will be in a mushy state.
