Periodic Table Element Comparison: Compare Elements - Aluminium vs Chromium
Compare Aluminium and Chromium
Compare Aluminium and Chromium on the basis of their properties, attributes and periodic table facts. Compare elements on more than 90 properties. All the elements of similar categories show a lot of similarities and differences in their chemical, atomic, physical properties and uses. These similarities and dissimilarities should be known while we study periodic table elements. You can study the detailed comparison between Aluminium vs Chromium with most reliable information about their properties, attributes, facts, uses etc. You can compare Al vs Cr on more than 90 properties like electronegativity , oxidation state, atomic shells, orbital structure, Electronaffinity, physical states, electrical conductivity and many more.
Facts
| Name | Aluminium | Chromium |
| Atomic Number | 13 | 24 |
| Atomic Symbol | Al | Cr |
| Atomic Weight | 26.981538 | 51.9961 |
| Phase at STP | Solid | Solid |
| Color | Silver | Silver |
| Metallic Classification | Post Transition Metal | Transition Metal |
| Group in Periodic Table | group 13 | group 6 |
| Group Name | boron family | chromium family |
| Period in Periodic Table | period 3 | period 4 |
| Block in Periodic Table | p -block | d -block |
| Electronic Configuration | [Ne] 3s2 3p1 | [Ar] 3d5 4s1 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 3 | 2, 8, 13, 1 |
| Melting Point | 933.47 K | 2180 K |
| Boiling Point | 2792 K | 2944 K |
| CAS Number | CAS7429-90-5 | CAS7440-47-3 |
| Neighborhood Elements | Neighborhood Elements of Aluminium | Neighborhood Elements of Chromium |
History
| Name | Aluminium | Chromium |
| History | The element Aluminium was discovered by H.C.Ørsted in year 1825 in Denmark. Aluminium derived its name from alumina, a compound (originally aluminum). | The element Chromium was discovered by N. Vauquelin in year 1797 in France. Chromium derived its name from the Greek word chroma, meaning 'color'. |
| Discovery | H.C.Ørsted (1825) | N. Vauquelin (1797) |
| Isolated | H.C.Ørsted (1825) | N. Vauquelin (1798) |
Presence: Abundance in Nature and Around Us
Parts per billion (ppb) by weight / by atoms (1ppb =10^-7 %)
| Name | Aluminium | Chromium |
| Abundance in Universe | 50000 / 2000 | 15000 / 400 |
| Abundance in Sun | 60000 / 3000 | 20000 / 400 |
| Abundance in Meteorites | 9300000 / 6700000 | 3100000 / 1200000 |
| Abundance in Earth's Crust | 82000000 / 63000000 | 140000 / 55000 |
| Abundance in Oceans | 5 / 1.1 | 0.6 / 0.071 |
| Abundance in Humans | 900 / 210 | 30 / 4 |
Crystal Structure and Atomic Structure
| Name | Aluminium | Chromium |
| Atomic Volume | 9.99 cm3/mol | 7.2824 cm3/mol |
| Atomic Radius | 118 pm | 166 pm |
| Covalent Radius | 118 pm | 127 pm |
| Van der Waals Radius | 184 pm | - |
| Atomic Spectrum - Spectral Lines | ||
| Emission Spectrum |  |  |
| Absorption Spectrum |  |  |
| Lattice Constant | 404.95, 404.95, 404.95 pm | 291, 291, 291 pm |
| Lattice Angle | π/2, π/2, π/2 | π/2, π/2, π/2 |
| Space Group Name | Fm_ 3m | Im_ 3m |
| Space Group Number | 225 | 229 |
| Crystal Structure | Face Centered Cubic  | Body Centered Cubic  |
Atomic and Orbital Properties
| Name | Aluminium | Chromium |
| Atomic Number | 13 | 24 |
| Number of Electrons (with no charge) | 13 | 24 |
| Number of Protons | 13 | 24 |
| Mass Number | 26.981538 | 51.9961 |
| Number of Neutrons | 14 | 28 |
| Shell structure (Electrons per energy level) | 2, 8, 3 | 2, 8, 13, 1 |
| Electron Configuration | [Ne] 3s2 3p1 | [Ar] 3d5 4s1 |
| Valence Electrons | 3s2 3p1 | 3d5 4s1 |
| Oxidation State | 3 | 2, 3, 6 |
| Atomic Term Symbol (Quantum Numbers) | 2P1/2 | 7S3 |
| Shell structure |  |  |
Isotopes and Nuclear Properties
Aluminium has 1 stable naturally occuring isotopes while Chromium has 4 stable naturally occuring isotopes.
| Name | Aluminium | Chromium |
| Known Isotopes | 21Al, 22Al, 23Al, 24Al, 25Al, 26Al, 27Al, 28Al, 29Al, 30Al, 31Al, 32Al, 33Al, 34Al, 35Al, 36Al, 37Al, 38Al, 39Al, 40Al, 41Al, 42Al | 42Cr, 43Cr, 44Cr, 45Cr, 46Cr, 47Cr, 48Cr, 49Cr, 50Cr, 51Cr, 52Cr, 53Cr, 54Cr, 55Cr, 56Cr, 57Cr, 58Cr, 59Cr, 60Cr, 61Cr, 62Cr, 63Cr, 64Cr, 65Cr, 66Cr, 67Cr |
| Stable Isotopes | Naturally occurring stable isotopes: 27Al | Naturally occurring stable isotopes: 50Cr, 52Cr, 53Cr, 54Cr |
| Neutron Cross Section | 0.233 | 3.1 |
| Neutron Mass Absorption | 0.03 | 0.0021 |
Chemical Properties: Ionization Energies and electron affinity
| Name | Aluminium | Chromium |
| Valence or Valency | 3 | 6 |
| Electronegativity | 1.61 Pauling Scale | 1.66 Pauling Scale |
| Electron Affinity | 42.5 kJ/mol | 64.3 kJ/mol |
| Ionization Energies | 1st: 577.5 kJ/mol 2nd: 1816.7 kJ/mol 3rd: 2744.8 kJ/mol 4th: 11577 kJ/mol 5th: 14842 kJ/mol 6th: 18379 kJ/mol 7th: 23326 kJ/mol 8th: 27465 kJ/mol 9th: 31853 kJ/mol 10th: 38473 kJ/mol 11th: 42647 kJ/mol 12th: 201266 kJ/mol 13th: 222316 kJ/mol | 1st: 652.9 kJ/mol 2nd: 1590.6 kJ/mol 3rd: 2987 kJ/mol 4th: 4743 kJ/mol 5th: 6702 kJ/mol 6th: 8744.9 kJ/mol 7th: 15455 kJ/mol 8th: 17820 kJ/mol 9th: 20190 kJ/mol 10th: 23580 kJ/mol 11th: 26130 kJ/mol 12th: 28750 kJ/mol 13th: 34230 kJ/mol 14th: 37066 kJ/mol 15th: 97510 kJ/mol 16th: 105800 kJ/mol 17th: 114300 kJ/mol 18th: 125300 kJ/mol 19th: 134700 kJ/mol 20th: 144300 kJ/mol 21st: 157700 kJ/mol 22nd: 166090 kJ/mol 23rd: 721870 kJ/mol 24th: 761733 kJ/mol |
Physical Properties
| Name | Aluminium | Chromium |
| Density | 2.7 g/cm3 | 7.14 g/cm3 |
| Molar Volume | 9.99 cm3/mol | 7.2824 cm3/mol |
Elastic Properties | ||
| Young Modulus | 70 | 279 |
| Shear Modulus | 26 GPa | 115 GPa |
| Bulk Modulus | 76 GPa | 160 GPa |
| Poisson Ratio | 0.35 | 0.21 |
Hardness - Tests to Measure of Hardness of Element | ||
| Mohs Hardness | 2.75 MPa | 8.5 MPa |
| Vickers Hardness | 167 MPa | 1060 MPa |
| Brinell Hardness | 245 MPa | 1120 MPa |
Electrical Properties | ||
| Electrical Conductivity | 38000000 S/m | 7900000 S/m |
| Resistivity | 2.6e-8 m Ω | 1.3e-7 m Ω |
| Superconducting Point | 1.175 | - |
Heat and Conduction Properties | ||
| Thermal Conductivity | 235 W/(m K) | 94 W/(m K) |
| Thermal Expansion | 0.0000231 /K | 0.0000049 /K |
Magnetic Properties | ||
| Magnetic Type | Paramagnetic | Antiferromagnetic |
| Curie Point | - | - |
| Mass Magnetic Susceptibility | 7.8e-9 m3/kg | 4.45e-8 m3/kg |
| Molar Magnetic Susceptibility | 2.1e-10 m3/mol | 2.314e-9 m3/mol |
| Volume Magnetic Susceptibility | 0.0000211 | 0.0003177 |
Optical Properties | ||
| Refractive Index | - | - |
Acoustic Properties | ||
| Speed of Sound | 5100 m/s | 5940 m/s |
Thermal Properties - Enthalpies and thermodynamics
| Name | Aluminium | Chromium |
| Melting Point | 933.47 K | 2180 K |
| Boiling Point | 2792 K | 2944 K |
| Critical Temperature | - | - |
| Superconducting Point | 1.175 | - |
Enthalpies | ||
| Heat of Fusion | 10.7 kJ/mol | 20.5 kJ/mol |
| Heat of Vaporization | 293 kJ/mol | 339 kJ/mol |
| Heat of Combustion | - | - |
Regulatory and Health - Health and Safety Parameters and Guidelines
| Name | Aluminium | Chromium |
| CAS Number | CAS7429-90-5 | CAS7440-47-3 |
| RTECS Number | RTECSBD0330000 | RTECSGB4200000 |
| DOT Hazard Class | 4.3 | 4.1 |
| DOT Numbers | 1396 | 3089 |
| EU Number | - | - |
| NFPA Fire Rating | 1 | 1 |
| NFPA Health Rating | 0 | 2 |
| NFPA Reactivity Rating | 1 | 1 |
| NFPA Hazards | - | - |
| AutoIgnition Point | 400 °C | 400 °C |
| Flashpoint | 645 °C | - |