Element 1 of Periodic table is Hydrogen with atomic number 1, atomic weight 1.00794. Hydrogen, symbol H, has a Simple Hexagonal structure and Colorless color. Hydrogen is a other nonmetal element. Trivial name of Hydrogen is alkali metals*. Know everything about Hydrogen Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass.
Read key information and facts about element Hydrogen
Name | Hydrogen |
Atomic Number | 1 |
Atomic Symbol | H |
Atomic Weight | 1.00794 |
Phase | Gas |
Color | Colorless |
Classification | other nonmetal |
Group in Periodic Table | 1 |
Group Name | lithium family |
Period in Periodic Table | 1 |
Block in Periodic Table | s-block |
Electronic Configuration | 1s1 |
Melting Point | -259.14 °C |
Boiling Point | -252.87 °C |
Electronic Shell Structure | [1] |
CAS Number | CAS1333-74-0 |
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 1 to find Hydrogen on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Hydrogen on periodic table look for cross section of group 1 and period 1 in the modern periodic table.
The element Hydrogen was discovered by Henry Cavendish in year 1766 in United Kingdom . Hydrogen derived its name from the Greek elements hydro- and -gen meaning 'water-forming'
The table below shows the abundance of Hydrogen in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
Ppb by weight (1ppb =10^-7 %) | |
---|---|
Abundance in Universe | 0.75 |
Abundance in Sun | 0.75 |
Abundance in Meteorites | 0.024 |
Abundance in Earth's Crust | 0.0015 |
Abundance in Oceans | 0.11 |
Abundance in Humans | 0.1 |
The solid state structure of Hydrogen is Simple Hexagonal.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
a | b | c |
---|---|---|
470 pm | 470 pm | 340 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
alpha | beta | gamma |
---|---|---|
π/2 | π/2 | 2 π/3 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
Space Group Name | P63/mmc |
![]() |
Space Group Number | 194 | |
Crystal Structure | Simple Hexagonal |
Hydrogen atoms have 1 electrons and the electronic shell structure is [1] with Atomic Term Symbol (Quantum Numbers) 2S1/2.
Atomic Number | 1 |
Number of Electrons (with no charge) | 1 |
Number of Protons | 1 |
Mass Number | 1 |
Number of Neutrons | 0 |
Shell structure (Electrons per energy level) | [1] |
Electron Configuration | 1s1 |
Valence Electrons | 1s1 |
Oxidation State |
-1
1 |
Atomic Term Symbol (Quantum Numbers) | 2S1/2 |
Shell Structure of Hydrogen - Electrons per energy level
n | s | p | d | f | |
---|---|---|---|---|---|
1 | K | 1 |
The ground state electronic configuration of Neutral Hydrogen atom is 1s1. The portion of Hydrogen configuration that is equivalent to the noble gas of the preceding period, is abbreviated as 1s1]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used.This is important as it is the Valence electrons 1s1, electrons in the outermost shell that determine the chemical properties of the element.
Complete ground state electronic configuration for the Hydrogen atom, Unabbreviated electronic configuration
1s1
Hydrogen atomic radius is 53 pm, while it's covalent radius is 37 pm.
Atomic Radius |
53 pm (0.53 Å) |
Atomic Volume | 11.2117908788 cm3 |
Covalent Radius | 37 pm (0.37 Å) |
Van der Waals Radius | 120 pm |
Neutron Cross Section | 0.332 σa/barns |
The electron affinity of Hydrogen is 72.8 kJ/mol
Valence | 1 |
Electronegativity | 2.2 |
ElectronAffinity | 72.8 kJ/mol |
Refer to table below for Ionization energies of Hydrogen
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1 | 1312 |
Refer to below table for Hydrogen Physical Properties
Density | 0.0899 g/l |
Molar Volume | 11.2117908788 cm3 |
Young Modulus | N/A |
Shear Modulus | N/A |
Bulk Modulus | N/A |
Poisson Ratio | N/A |
Mohs Hardness | N/A |
Vickers Hardness | N/A |
Brinell Hardness | N/A |
Hydrogen is N/A of electricity. Refer to table below for the Electrical properties of Hydrogen
Electrical Conductivity | N/A |
Resistivity | N/A |
Superconducting Point | N/A |
Thermal Conductivity | 0.1805 W/(m K) |
Thermal Expansion | N/A |
Magnetic Type | Diamagnetic |
Curie Point | N/A |
Mass Magnetic Susceptibility | -2.48×10-8 |
Molar Magnetic Susceptibility | -4.999×10-11 |
Volume Magnetic Susceptibility | -2.23×10-9 |
Refractive Index | 1.000132 |
Speed of Sound | 1270 m/s |
Refer to table below for Thermal properties of Hydrogen
Melting Point | 14.01 K (-259.14 °C) |
Boiling Point | 20.28 K (-252.87 °C) |
Critical Temperature | 32.97 K |
Superconducting Point | N/A |
Heat of Fusion | 0.558 kJ/mol |
Heat of Vaporization | 0.452 kJ/mol |
Heat of Combustion | N/A |
Isotopes of rhodium. Naturally occurring Hydrogen has 2 stable isotope - 1H, 2H.
Isotope | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|
1H | - | Stable | N/A | |
2H | Stable | N/A | ||
3H | ||||
4H | ||||
5H | ||||
6H | ||||
7H |
CAS Number | CAS1333-74-0 |
RTECS Number | RTECSMW8900000 |
DOT Hazard Class | 2.1 |
DOT Numbers | 1966 |
EU Number | N/A |
NFPA Fire Rating | 4 |
NFPA Hazards | N/A |
NFPA Health Rating | 3 |
NFPA Reactivity Rating | 0 |
Autoignition Point | 535.5 °C |
Flashpoint | -18 °C |
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS1333-74-0 |
CID Number | CID783 |
Gmelin Number | N/A |
NSC Number | N/A |
RTECS Number | RTECSMW8900000 |
Metalloid |
Nonmetals |
Other Nonmetals | |
Halogens | Noble Gas |
Metals |
|
Alkali Metals | Alkaline Earth Metals |
Transition Metals | Post-Transition Metals |
Lanthanide | Actinide |