Periodic Table Element Comparison: Compare Elements - Argon vs Helium
Compare Argon and Helium 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 Argon vs Helium with most reliable information about their properties, attributes, facts, uses etc. You can compare Ar vs He on more than 90 properties like electronegativity , oxidation state, atomic shells, orbital structure, Electronaffinity, physical states, electrical conductivity and many more. Argon and Helium comparison table on more than 90 properties.
Argon and Helium Comparison
Facts
| Name | Argon | Helium |
|---|---|---|
| Atomic Number | 18 | 2 |
| Atomic Symbol | Ar | He |
| Atomic Weight | 39.948 | 4.002602 |
| Phase at STP | Gas | Gas |
| Color | Colorless | Colorless |
| Metallic Classification | Noble Gas | Noble Gas |
| Group in Periodic Table | group 18 | group 18 |
| Group Name | helium family or neon family | helium family or neon family |
| Period in Periodic Table | period 3 | period 1 |
| Block in Periodic Table | p -block | p -block |
| Electronic Configuration | [Ne] 3s2 3p6 | 1s2 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 8 | 2 |
| Melting Point | 83.8 K | 0 K |
| Boiling Point | 87.3 K | 4.22 K |
| CAS Number | CAS7440-37-1 | CAS7440-59-7 |
| Neighborhood Elements | Neighborhood Elements of Argon | Neighborhood Elements of Helium |
History
| Parameter | Argon | Helium |
|---|---|---|
| History | The element Argon was discovered by Lord Rayleigh and W. Ramsay in year 1894 in United Kingdom. Argon derived its name from the Greek word argos, meaning 'idle'. | The element Helium was discovered by P. Janssen and N. Lockyer in year 1868 in Sweden and United Kingdom. Helium derived its name from the Greek word helios, meaning 'sun'. |
| Discovery | Lord Rayleigh and W. Ramsay (1894) | P. Janssen and N. Lockyer (1868) |
| Isolated | Lord Rayleigh and W. Ramsay (1894) | W. Ramsay,T. Cleve, and N. Langlet (1895) |
Presence: Abundance in Nature and Around Us
Parts per billion (ppb) by weight / by atoms (1ppb =10^-7 %)
| Property | Argon | Helium |
|---|---|---|
| Abundance in Universe | 200000 / 6000 | 230000000 / 72000000 |
| Abundance in Sun | 70000 / 2000 | 230000000 / 74000000 |
| Abundance in Meteorites | - / - | - / - |
| Abundance in Earth's Crust | 1500 / 780 | 5.5 / 30 |
| Abundance in Oceans | 450 / 70 | 0.0072 / 0.011 |
| Abundance in Humans | - / - | - / - |
Crystal Structure and Atomic Structure
| Property | Argon | Helium |
|---|---|---|
| Atomic Volume | 22.4134 cm3/mol | 22.4136 cm3/mol |
| Atomic Radius | 71 pm | 31 pm |
| Covalent Radius | 97 pm | 32 pm |
| Van der Waals Radius | 188 pm | 140 pm |
Atomic Spectrum - Spectral Lines | ||
| Emission Spectrum |  |  |
| Absorption Spectrum |  |  |
| Lattice Constant | 525.6, 525.6, 525.6 pm | 424.2, 424.2, 424.2 pm |
| Lattice Angle | π/2, π/2, π/2 | π/2, π/2, π/2 |
| Space Group Name | Fm_ 3m | Fm_ 3m |
| Space Group Number | 225 | 225 |
| Crystal Structure | Face Centered Cubic  | Face Centered Cubic |
Atomic and Orbital Properties
| Property | Argon | Helium |
|---|---|---|
| Atomic Number | 18 | 2 |
| Number of Electrons (with no charge) | 18 | 2 |
| Number of Protons | 18 | 2 |
| Mass Number | 39.948 | 4.002602 |
| Number of Neutrons | 22 | 2 |
| Shell structure (Electrons per energy level) | 2, 8, 8 | 2 |
| Electron Configuration | [Ne] 3s2 3p6 | 1s2 |
| Valence Electrons | 3s2 3p6 | 1s2 |
| Oxidation State | 0 | - |
| Atomic Term Symbol (Quantum Numbers) | 1S0 | 1S0 |
| Shell structure |  |  |
Isotopes and Nuclear Properties
Argon has 3 stable naturally occuring isotopes while Helium has 2 stable naturally occuring isotopes.
| Parameter | Argon | Helium |
|---|---|---|
| Known Isotopes | 30Ar, 31Ar, 32Ar, 33Ar, 34Ar, 35Ar, 36Ar, 37Ar, 38Ar, 39Ar, 40Ar, 41Ar, 42Ar, 43Ar, 44Ar, 45Ar, 46Ar, 47Ar, 48Ar, 49Ar, 50Ar, 51Ar, 52Ar, 53Ar | 3He, 4He, 5He, 6He, 7He, 8He, 9He, 10He |
| Stable Isotopes | Naturally occurring stable isotopes: 36Ar, 38Ar, 40Ar | Naturally occurring stable isotopes: 3He, 4He |
| Neutron Cross Section | 0.65 | 0.007 |
| Neutron Mass Absorption | 0.0006 | 0.00001 |
Chemical Properties: Ionization Energies and electron affinity
| Property | Argon | Helium |
|---|---|---|
| Valence or Valency | 0 | 0 |
| Electronegativity | - | - |
| Electron Affinity | 0 kJ/mol | 0 kJ/mol |
| Ionization Energies | 1st: 1520.6 kJ/mol 2nd: 2665.8 kJ/mol 3rd: 3931 kJ/mol 4th: 5771 kJ/mol 5th: 7238 kJ/mol 6th: 8781 kJ/mol 7th: 11995 kJ/mol 8th: 13842 kJ/mol 9th: 40760 kJ/mol 10th: 46186 kJ/mol 11th: 52002 kJ/mol 12th: 59653 kJ/mol 13th: 66199 kJ/mol 14th: 72918 kJ/mol 15th: 82473 kJ/mol 16th: 88576 kJ/mol 17th: 397605 kJ/mol 18th: 427066 kJ/mol | 1st: 2372.3 kJ/mol 2nd: 5250.5 kJ/mol |
Physical Properties
| Property | Argon | Helium |
|---|---|---|
| Density | 0.001784 g/cm3 | 0.0001785 g/cm3 |
| Molar Volume | 22.4134 cm3/mol | 22.4136 cm3/mol |
Elastic Properties | ||
| Young Modulus | - | - |
| Shear Modulus | - | - |
| Bulk Modulus | - | - |
| Poisson Ratio | - | - |
Hardness - Tests to Measure of Hardness of Element | ||
| Mohs Hardness | - | - |
| Vickers Hardness | - | - |
| Brinell Hardness | - | - |
Electrical Properties | ||
| Electrical Conductivity | - | - |
| Resistivity | - | - |
| Superconducting Point | - | - |
Heat and Conduction Properties | ||
| Thermal Conductivity | 0.01772 W/(m K) | 0.1513 W/(m K) |
| Thermal Expansion | - | - |
Magnetic Properties | ||
| Magnetic Type | Diamagnetic | Diamagnetic |
| Curie Point | - | - |
| Mass Magnetic Susceptibility | -6e-9 m3/kg | -5.9e-9 m3/kg |
| Molar Magnetic Susceptibility | -2.4e-10 m3/mol | -2.36e-11 m3/mol |
| Volume Magnetic Susceptibility | -1.07e-8 | -1.05e-9 |
Optical Properties | ||
| Refractive Index | 1.000281 | 1.000035 |
Acoustic Properties | ||
| Speed of Sound | 319 m/s | 970 m/s |
Thermal Properties - Enthalpies and thermodynamics
| Property | Argon | Helium |
|---|---|---|
| Melting Point | 83.8 K | 0 K |
| Boiling Point | 87.3 K | 4.22 K |
| Critical Temperature | 150.87 K | 5.19 K |
| Superconducting Point | - | - |
Enthalpies | ||
| Heat of Fusion | 1.18 kJ/mol | 0.02 kJ/mol |
| Heat of Vaporization | 6.5 kJ/mol | 0.083 kJ/mol |
| Heat of Combustion | - | - |
Regulatory and Health - Health and Safety Parameters and Guidelines
| Parameter | Argon | Helium |
|---|---|---|
| CAS Number | CAS7440-37-1 | CAS7440-59-7 |
| RTECS Number | RTECSCF2300000 | RTECSMH6520000 |
| DOT Hazard Class | 2.2 | 2.2 |
| DOT Numbers | 1951 | 1963 |
| EU Number | - | - |
| NFPA Fire Rating | - | 0 |
| NFPA Health Rating | - | 1 |
| NFPA Reactivity Rating | - | 0 |
| NFPA Hazards | - | - |
| AutoIgnition Point | - | - |
| Flashpoint | - | - |
Compare With Other Elements
Compare Argon and Helium with other elements of the periodic table.
Compare Argon with all Group 18 elementsCompare Argon with HeliumCompare Argon with NeonCompare Argon with KryptonCompare Argon with XenonCompare Argon with RadonCompare Argon with Oganesson Compare Argon with all Period 3 elementsCompare Argon with SodiumCompare Argon with MagnesiumCompare Argon with AluminiumCompare Argon with SiliconCompare Argon with PhosphorusCompare Argon with SulfurCompare Argon with Chlorine Compare Argon with all Noble Gas elements | Compare Helium with all Group 18 elementsHelium vs Neon ComparisonHelium vs Argon ComparisonHelium vs Krypton ComparisonHelium vs Xenon ComparisonHelium vs Radon ComparisonHelium vs Oganesson Comparison Compare Helium with all Period 1 elementsCompare Helium with all Noble Gas elements |