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.
It belongs to group 1 of the periodic table having trivial name alkali metals*.
Read key information and facts about element Hydrogen
|Phase||Gas (Diatomic Gas )|
|Group in Periodic Table||1|
|Group Name||lithium family|
|Period in Periodic Table||period 1|
|Block in Periodic Table||s -block|
|Electronic Shell Structure (Electrons per shell)||1|
|Melting Point||14.01 K|
|Boiling Point||20.28 K|
How to Locate Hydrogen on Periodic Table
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 H. Cavendish in year 1766 in United Kingdom. Hydrogen was first isolated by Paracelsus in 1500. Hydrogen derived its name from the Greek elements hydro- and -gen meaning 'water-forming'.
Cavendish was the first to distinguish from other gases, although Paracelsus around 1500, Robert Boyle, and Joseph Priestley had observed its production by reacting strong acids with metals. Lavoisier named it in 1793.
Hydrogen Presence: Abundance in Nature and Around Us
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 %)||ppb by atoms (1ppb =10^-7 %)|
|Abundance in Universe||750000000||930000000|
|Abundance in Sun||750000000||930000000|
|Abundance in Meteorites||24000000||170000000|
|Abundance in Earth's Crust||1500000||31000000|
|Abundance in Oceans||107800000||662000000|
|Abundance in Humans||100000000||620000000|
Crystal Structure of Hydrogen
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.
Unit Cell Parameters
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)
|470 pm||470 pm||340 pm|
and the angles between them Lattice Angles (alpha, beta and gamma).
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|
|Number of atoms per unit cell|
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Hydrogen Atomic and Orbital Properties
Hydrogen atoms have 1 electrons and the electronic shell structure is  with Atomic Term Symbol (Quantum Numbers) 2S1/2.
|Number of Electrons (with no charge)||1|
|Number of Protons||1|
|Number of Neutrons||0|
|Shell structure (Electrons per energy level)||1|
|Main Oxidation States||-1, 1|
|Oxidation States||-1, 1|
|Atomic Term Symbol (Quantum Numbers)||2S1/2|
Bohr Atomic Model of Hydrogen - Electrons per energy level
Ground State Electronic Configuration of Hydrogen - neutral Hydrogen atom
Abbreviated electronic configuration of Hydrogen
The ground state abbreviated 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 . 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.
Unabbreviated electronic configuration of neutral Hydrogen
Complete ground state electronic configuration for the Hydrogen atom, Unabbreviated electronic configuration
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
Atomic Structure of Hydrogen
Hydrogen atomic radius is 53 pm, while it's covalent radius is 37 pm.
|Atomic Radius Calculated|
53 pm (0.53 Å)
|Atomic Radius Empirical|
25 pm (0.25 Å)
|Atomic Volume||22.4135 cm3/mol|
|Covalent Radius||37 pm (0.37 Å)|
|Van der Waals Radius||120 pm|
|Neutron Cross Section||0.332|
|Neutron Mass Absorption||0.011|
Atomic Spectrum of Hydrogen
Hydrogen Chemical Properties: Hydrogen Ionization Energies and electron affinity
The electron affinity of Hydrogen is 72.8 kJ/mol.
Ionization Energy of Hydrogen
Refer to table below for Ionization energies of Hydrogen
|Ionization energy number||Enthalpy - kJ/mol|
Hydrogen Physical Properties
Refer to below table for Hydrogen Physical Properties
|Molar Volume||22.4135 cm3/mol|
Hardness of Hydrogen - Tests to Measure of Hardness of Element
Hydrogen Electrical Properties
Hydrogen is Conductor of electricity. Refer to table below for the Electrical properties ofHydrogen
Hydrogen Heat and Conduction Properties
|Thermal Conductivity||0.1805 W/(m K)|
Hydrogen Magnetic Properties
|Mass Magnetic Susceptibility||-2.48e-8 m3/kg|
|Molar Magnetic Susceptibility||-4.999e-11 m3/mol|
|Volume Magnetic Susceptibility||-2.23e-9|
Optical Properties of Hydrogen
Acoustic Properties of Hydrogen
|Speed of Sound||1270 m/s|
Hydrogen Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Hydrogen
|Melting Point||14.01 K (-259.14°C, -434.45199999999994 °F)|
|Boiling Point||20.28 K (-252.87°C, -423.166 °F)|
|Critical Temperature||32.97 K|
Enthalpies of Hydrogen
|Heat of Fusion||0.558 kJ/mol|
|Heat of Vaporization||0.452 kJ/mol|
|Heat of Combustion||-|
Hydrogen Isotopes - Nuclear Properties of Hydrogen
Hydrogen has 7 isotopes, with between 1 and 7 nucleons. Hydrogen has 2 stable naturally occuring isotopes.
Isotopes of Hydrogen - Naturally occurring stable Isotopes: 1H, 2H.
|Isotope||Z||N||Isotope Mass||% Abundance||T half||Decay Mode|
Compare Hydrogen with other elements
Compare Hydrogen with all Group 1 elements
Compare Hydrogen with all Period 1 elements
Compare Hydrogen with all Other Nonmetal elements
What is the electronic configuration of Hydrogen?
The electronic configuration of Hydrogen is 1s1.
What is the abbreviated electronic configuration of Hydrogen?
The abbreviated electronic configuration of Hydrogen is 1s1. To form abbreviated notation of electronic configuration, the completely filled subshells are replaced by the noble gas of the preceding period in square brackets.
What is the symbol of Hydrogen?
Symbol of Hydrogen is H. Hydrogen is a chemical element with symbol H and atomic number 1.
What is the position of Hydrogen in the Periodic Table?
Hydrogen is a chemical element with the symbol H and atomic number 1. Hydrogen is the 1 element on the periodic table. It is located in group 1 and period 1 in the modern periodic table.
What is the atomic number of Hydrogen?
The atomic number of Hydrogen is 1.
What is the color of Hydrogen?
Hydrogen is Colorless.
Who discovered Hydrogen?
The element Hydrogen was discovered by H. Cavendish in year 1766 in United Kingdom. Hydrogen was first isolated by Paracelsus in 1500.
How many valence electrons does a Hydrogen atom have?
Hydrogen has 1 valence electrons. Hydrogen has 1 electrons out of which 1 valence electrons are present in the 1s1 outer orbitals of atom.
What is the melting Point of Hydrogen?
Melting Point of Hydrogen is 14.01 K.
What is the boiling Point of Hydrogen?
Boiling Point of Hydrogen is 20.28 K.
What is the melting Point of Hydrogen in Kelvin?
Melting Point of Hydrogen in Kelvin is 14.01 K.
What is the boiling Point of Hydrogen in Kelvin?
Boiling Point of Hydrogen in Kelvin is 20.28 K.
What is the electronic configuration of Hydrogen 1?
The electronic configuration of Hydrogen will be 1s1.
How do you write the electron configuration for Hydrogen?
The electronic configuration of Hydrogen will be 1s1.