Compare Helium vs Hydrogen: Periodic Table Element Comparison Table and Properties
Compare the elements Helium and Hydrogen on the basis of their properties, attributes and periodic table facts. Compare elements - Helium and Hydrogen comparison table side by side across over 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 Helium vs Hydrogen with most reliable information about their properties, attributes, facts, uses etc. You can compare He vs H on more than 90 properties like electronegativity, oxidation state, atomic shells, orbital structure, Electronaffinity, physical states, electrical conductivity and many more. This in-depth comparison helps students, educators, researchers, and science enthusiasts understand the differences and similarities between Helium and Hydrogen.
Helium and Hydrogen Comparison
Here's a detailed comparison between Helium (He) and Hydrogen (H), focusing on their position in the periodic table, physical and chemical properties, stability, and uses.
Facts - Basic Element Details
| Name | Helium | Hydrogen |
|---|---|---|
| Atomic Number | 2 | 1 |
| Atomic Symbol | He | H |
| Atomic Weight | 4.002602 | 1.00794 |
| Phase at STP | Gas | Gas |
| Color | Colorless | Colorless |
| Metallic Classification | Noble Gas | Other Nonmetal |
| Group in Periodic Table | group 18 | group 1 |
| Group Name | helium family or neon family | lithium family |
| Period in Periodic Table | period 1 | period 1 |
| Block in Periodic Table | p -block | s -block |
| Electronic Configuration | 1s2 | 1s1 |
| Electronic Shell Structure (Electrons per shell) | 2 | 1 |
| Melting Point | 0 K | 14.01 K |
| Boiling Point | 4.22 K | 20.28 K |
| CAS Number | CAS7440-59-7 | CAS1333-74-0 |
| Neighborhood Elements | Neighborhood Elements of Helium | Neighborhood Elements of Hydrogen |
History
| Parameter | Helium | Hydrogen |
|---|---|---|
| History | 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'. | The element Hydrogen was discovered by H. Cavendish in year 1766 in United Kingdom. Hydrogen derived its name from the Greek elements hydro- and -gen meaning 'water-forming'. |
| Discovery | P. Janssen and N. Lockyer (1868) | H. Cavendish (1766) |
| Isolated | W. Ramsay,T. Cleve, and N. Langlet (1895) | Paracelsus (1500) |
Presence: Abundance in Nature and Around Us
Parts per billion (ppb) by weight / by atoms (1ppb =10^-7 %)
| Property | Helium | Hydrogen |
|---|---|---|
| Abundance in Universe | 230000000 / 72000000 | 750000000 / 930000000 |
| Abundance in Sun | 230000000 / 74000000 | 750000000 / 930000000 |
| Abundance in Meteorites | - / - | 24000000 / 170000000 |
| Abundance in Earth's Crust | 5.5 / 30 | 1500000 / 31000000 |
| Abundance in Oceans | 0.0072 / 0.011 | 107800000 / 662000000 |
| Abundance in Humans | - / - | 100000000 / 620000000 |
Crystal Structure and Atomic Structure
| Property | Helium | Hydrogen |
|---|---|---|
| Atomic Volume | 22.4136 cm3/mol | 22.4135 cm3/mol |
| Atomic Radius | 31 pm | 53 pm |
| Covalent Radius | 32 pm | 37 pm |
| Van der Waals Radius | 140 pm | 120 pm |
Atomic Spectrum - Spectral Lines | ||
| Emission Spectrum |  |  |
| Absorption Spectrum |  |  |
| Lattice Constant | 424.2, 424.2, 424.2 pm | 470, 470, 340 pm |
| Lattice Angle | π/2, π/2, π/2 | π/2, π/2, 2 π/3 |
| Space Group Name | Fm_ 3m | P63/mmc |
| Space Group Number | 225 | 194 |
| Crystal Structure | Face Centered Cubic  | Simple Hexagonal  |
Atomic and Orbital Properties
| Property | Helium | Hydrogen |
|---|---|---|
| Atomic Number | 2 | 1 |
| Number of Electrons (with no charge) | 2 | 1 |
| Number of Protons | 2 | 1 |
| Mass Number | 4.002602 | 1.00794 |
| Number of Neutrons | 2 | 0 |
| Shell structure (Electrons per energy level) | 2 | 1 |
| Electron Configuration | 1s2 | 1s1 |
| Valence Electrons | 1s2 | 1s1 |
| Oxidation State | - | -1, 1 |
| Atomic Term Symbol (Quantum Numbers) | 1S0 | 2S1/2 |
| Shell structure |  |  |
Isotopes and Nuclear Properties
Helium has 2 stable naturally occuring isotopes while Hydrogen has 2 stable naturally occuring isotopes.
| Parameter | Helium | Hydrogen |
|---|---|---|
| Known Isotopes | 3He, 4He, 5He, 6He, 7He, 8He, 9He, 10He | 1H, 2H, 3H, 4H, 5H, 6H, 7H |
| Stable Isotopes | Naturally occurring stable isotopes: 3He, 4He | Naturally occurring stable isotopes: 1H, 2H |
| Neutron Cross Section | 0.007 | 0.332 |
| Neutron Mass Absorption | 0.00001 | 0.011 |
Chemical Properties: Ionization Energies and electron affinity
| Property | Helium | Hydrogen |
|---|---|---|
| Valence or Valency | 0 | 1 |
| Electronegativity | - | 2.2 Pauling Scale |
| Oxidation State | - | -1, 1 |
| Electron Affinity | 0 kJ/mol | 72.8 kJ/mol |
| Ionization Energies | 1st: 2372.3 kJ/mol 2nd: 5250.5 kJ/mol | 1st: 1312 kJ/mol |
Physical Properties
Hydrogen (0.0000899 g/cm³) is less dense than Helium (0.0001785 g/cm³). This means that a given volume of Helium will be heavier than the same volume of Hydrogen. Helium is about 98.6 denser than Hydrogen
| Property | Helium | Hydrogen |
|---|---|---|
| Phase at STP | Gas | Gas |
| Color | Colorless | Colorless |
| Density | 0.0001785 g/cm3 | 0.0000899 g/cm3 |
| Density (when liquid (at melting point)) | - | - |
| Molar Volume | 22.4136 cm3/mol | 22.4135 cm3/mol |
Mechanical and Hardness Properties
| Property | Helium | Hydrogen |
|---|---|---|
Elastic Properties | ||
| Young Modulus | - | - |
| Shear Modulus | - | - |
| Bulk Modulus | - | - |
| Poisson Ratio | - | - |
Hardness - Tests to Measure of Hardness of Element | ||
| Mohs Hardness | - | - |
| Vickers Hardness | - | - |
| Brinell Hardness | - | - |
Thermal and Electrical Conductivity
| Property | Helium | Hydrogen |
|---|---|---|
Heat and Conduction Properties | ||
| Thermal Conductivity | 0.1513 W/(m K) | 0.1805 W/(m K) |
| Thermal Expansion | - | - |
Electrical Properties | ||
| Electrical Conductivity | - | - |
| Resistivity | - | - |
| Superconducting Point | - | - |
Magnetic and Optical Properties
| Property | Helium | Hydrogen |
|---|---|---|
Magnetic Properties | ||
| Magnetic Type | Diamagnetic | Diamagnetic |
| Curie Point | - | - |
| Mass Magnetic Susceptibility | -5.9e-9 m3/kg | -2.48e-8 m3/kg |
| Molar Magnetic Susceptibility | -2.36e-11 m3/mol | -4.999e-11 m3/mol |
| Volume Magnetic Susceptibility | -1.05e-9 | -2.23e-9 |
Optical Properties | ||
| Refractive Index | 1.000035 | 1.000132 |
Acoustic Properties | ||
| Speed of Sound | 970 m/s | 1270 m/s |
Thermal Properties - Enthalpies and thermodynamics
| Property | Helium | Hydrogen |
|---|---|---|
| Melting Point | 0 K | 14.01 K |
| Boiling Point | 4.22 K | 20.28 K |
| Critical Temperature | 5.19 K | 32.97 K |
| Superconducting Point | - | - |
Enthalpies | ||
| Heat of Fusion | 0.02 kJ/mol | 0.558 kJ/mol |
| Heat of Vaporization | 0.083 kJ/mol | 0.452 kJ/mol |
| Heat of Combustion | - | - |
Regulatory and Health - Health and Safety Parameters and Guidelines
| Parameter | Helium | Hydrogen |
|---|---|---|
| CAS Number | CAS7440-59-7 | CAS1333-74-0 |
| RTECS Number | RTECSMH6520000 | RTECSMW8900000 |
| DOT Hazard Class | 2.2 | 2.1 |
| DOT Numbers | 1963 | 1966 |
| EU Number | - | - |
| NFPA Fire Rating | 0 | 4 |
| NFPA Health Rating | 1 | 3 |
| NFPA Reactivity Rating | 0 | 0 |
| NFPA Hazards | - | - |
| AutoIgnition Point | - | 535.5 °C |
| Flashpoint | - | -18 °C |
Compare Helium and Hydrogen With Other Elements
Compare Helium and Hydrogen with other elements of the periodic table. Explore howHelium and Hydrogen stack up against other elements of the periodic table. Use our interactive comparison tool to analyze 90+ properties across different metals, non-metals, metalloids, and noble gases. Understanding these differences is crucial for applications in engineering, chemistry, electronics, biology, and material science.
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