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H Hydrogen
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

1
H
Hydrogen
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. It is part of group 1 (lithium family). Know everything about Hydrogen Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
1 H - Hydrogen | SchoolMyKids

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*. Hydrogen resides within this column, but is not considered an alkali metal.

Hydrogen Facts

Read key information and facts about element Hydrogen

NameHydrogen
Atomic Number1
Atomic SymbolH
Atomic Weight1.00794
PhaseGas (Diatomic Gas )
ColorColorless
Appearancecolorless gas
ClassificationOther Nonmetal
Group in Periodic Table1
Group Namelithium family
Period in Periodic Tableperiod 1
Block in Periodic Tables -block
Electronic Configuration1s1
Electronic Shell Structure (Electrons per shell)1
Melting Point14.01 K
Boiling Point20.28 K
CAS NumberCAS1333-74-0
Neighborhood Elements
123456789101112131415161718
1
1
H
Hydrogen
1.008

Atomic #

Electronic Shell #

Symbol
Name
Atomic Weight
HGas
HgLiquid
CSolid
Metals
Metalloids
NonMetals
Alkali metals
Alkali earth metals
Lanthanoids
Transition metals
Post-transition metals
Other nonmetals
Halogens
Nobel gas
Actinoids
2
He
Helium
4.003
2
3
Li
Lithium
6.941
4
Be
Beryllium
9.012
5
B
Boron
10.811
6
C
Carbon
12.011
7
N
Nitrogen
14.007
8
O
Oxygen
15.999
9
F
Fluorine
18.998
10
Ne
Neon
20.180
3
11
Na
Sodium
22.990
12
Mg
Magnesium
24.305
13
Al
Aluminium
26.982
14
Si
Silicon
28.085
15
P
Phosphorus
30.974
16
S
Sulfur
32.065
17
Cl
Chlorine
35.453
18
Ar
Argon
39.948
4
19
K
Potassium
39.098
20
Ca
Calcium
40.078
21
Sc
Scandium
44.956
22
Ti
Titanium
47.867
23
V
Vanadium
50.941
24
Cr
Chromium
51.996
25
Mn
Manganese
54.938
26
Fe
Iron
55.845
27
Co
Cobalt
58.933
28
Ni
Nickel
58.693
29
Cu
Copper
63.546
30
Zn
Zinc
65.409
31
Ga
Gallium
69.723
32
Ge
Germanium
72.640
33
As
Arsenic
74.922
34
Se
Selenium
78.960
35
Br
Bromine
79.904
36
Kr
Krypton
83.798
5
37
Rb
Rubidium
85.468
38
Sr
Strontium
87.620
39
Y
Yttrium
88.906
40
Zr
Zirconium
91.224
41
Nb
Niobium
92.906
42
Mo
Molybdenum
95.940
43
Tc
Technetium
98
44
Ru
Ruthenium
101.070
45
Rh
Rhodium
102.906
46
Pd
Palladium
106.420
47
Ag
Silver
107.868
48
Cd
Cadmium
112.411
49
In
Indium
114.818
50
Sn
Tin
118.710
51
Sb
Antimony
121.760
52
Te
Tellurium
127.600
53
I
Iodine
126.904
54
Xe
Xenon
131.293
6
55
Cs
Cesium
132.905
56
Ba
Barium
137.327
57 - 71
La - Lu
Lanthanides
72
Hf
Hafnium
178.490
73
Ta
Tantalum
180.948
74
W
Tungsten
183.840
75
Re
Rhenium
186.207
76
Os
Osmium
190.230
77
Ir
Iridium
192.217
78
Pt
Platinum
195.078
79
Au
Gold
196.967
80
Hg
Mercury
200.590
81
Tl
Thallium
204.383
82
Pb
Lead
207.200
83
Bi
Bismuth
208.980
84
Po
Polonium
209
85
At
Astatine
210
86
Rn
Radon
222
7
87
Fr
Francium
223
88
Ra
Radium
226
89 - 103
Ac - Lr
Actinides
104
Rf
Rutherfordium
261
105
Db
Dubnium
262
106
Sg
Seaborgium
266
107
Bh
Bohrium
264
108
Hs
Hassium
277
109
Mt
Meitnerium
268
110
Ds
Darmstadtium
281
111
Rg
Roentgenium
272
112
Cn
Copernicium
285
113
Nh
Nihonium
284
114
Fl
Flerovium
289
115
Mc
Moscovium
288
116
Lv
Livermorium
292
117
Ts
Tennessine
294
118
Og
Oganesson
294
Lanthanides
57
La
Lanthanum
138.905
58
Ce
Cerium
140.116
59
Pr
Praseodymium
140.908
60
Nd
Neodymium
144.240
61
Pm
Promethium
145
62
Sm
Samarium
150.360
63
Eu
Europium
151.964
64
Gd
Gadolinium
157.250
65
Tb
Terbium
158.925
66
Dy
Dysprosium
162.500
67
Ho
Holmium
164.930
68
Er
Erbium
167.259
69
Tm
Thulium
168.934
70
Yb
Ytterbium
173.040
71
Lu
Lutetium
174.967
Actinides
89
Ac
Actinium
227
90
Th
Thorium
232.038
91
Pa
Protactinium
231.036
92
U
Uranium
238.029
93
Np
Neptunium
237
94
Pu
Plutonium
244
95
Am
Americium
243
96
Cm
Curium
247
97
Bk
Berkelium
247
98
Cf
Californium
251
99
Es
Einsteinium
252
100
Fm
Fermium
257
101
Md
Mendelevium
258
102
No
Nobelium
259
103
Lr
Lawrencium
262

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.

Hydrogen History

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 Universe750000000930000000
Abundance in Sun750000000930000000
Abundance in Meteorites24000000170000000
Abundance in Earth's Crust150000031000000
Abundance in Oceans107800000662000000
Abundance in Humans100000000620000000

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)

abc
470 pm470 pm340 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alphabetagamma
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 NameP63/mmc 1 H Hydrogen - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number194
Crystal StructureSimple Hexagonal

Hydrogen Atomic and Orbital Properties

Hydrogen atoms have 1 electrons and the electronic shell structure is [1] with Atomic Term Symbol (Quantum Numbers) 2S1/2.

Atomic Number1
Number of Electrons (with no charge)1
Number of Protons1
Mass Number1
Number of Neutrons0
Shell structure (Electrons per energy level)1
Electron Configuration1s1
Valence Electrons1s1
Valence (Valency)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

1 H Hydrogen - Electron Shell Structure | SchoolMyKids
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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

1s1

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

  • As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
  • The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
  • Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
  • Electron configuration of Hydrogen
    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 Volume22.4135 cm3/mol
    Covalent Radius37 pm (0.37 Å)
    Van der Waals Radius120 pm
    Neutron Cross Section0.332
    Neutron Mass Absorption 0.011

    Atomic Spectrum of Hydrogen

    Atomic Spectrum of Hydrogen | SchoolMyKids

    Hydrogen Chemical Properties: Hydrogen Ionization Energies and electron affinity

    The electron affinity of Hydrogen is 72.8 kJ/mol.

    Valence1
    Electronegativity2.2
    ElectronAffinity72.8 kJ/mol

    Ionization Energy of Hydrogen

    Refer to table below for Ionization energies of Hydrogen

    Ionization energy numberEnthalpy - kJ/mol
    1st1312

    Hydrogen Physical Properties

    Refer to below table for Hydrogen Physical Properties

    Density0.0000899 g/cm3
    Molar Volume22.4135 cm3/mol

    Elastic Properties

    Young Modulus-
    Shear Modulus-
    Bulk Modulus -
    Poisson Ratio-

    Hardness of Hydrogen - Tests to Measure of Hardness of Element

    Mohs Hardness-
    Vickers Hardness-
    Brinell Hardness-

    Hydrogen Electrical Properties

    Hydrogen is Conductor of electricity. Refer to table below for the Electrical properties ofHydrogen

    Electrical Conductivity-
    Resistivity-
    Superconducting Point-

    Hydrogen Heat and Conduction Properties

    Thermal Conductivity0.1805 W/(m K)
    Thermal Expansion-

    Hydrogen Magnetic Properties

    Magnetic TypeDiamagnetic
    Curie Point-
    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

    Refractive Index1.000132

    Acoustic Properties of Hydrogen

    Speed of Sound1270 m/s

    Hydrogen Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Hydrogen

    Melting Point14.01 K (-259.14°C, -434.45199999999994 °F)
    Boiling Point20.28 K (-252.87°C, -423.166 °F)
    Critical Temperature32.97 K
    Superconducting Point-

    Enthalpies of Hydrogen

    Heat of Fusion0.558 kJ/mol
    Heat of Vaporization0.452 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.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    1H10199.9885%Stable
    2H1120.0115%StableN/A
    3H123Synthetic
    4H134Synthetic
    5H145Synthetic
    6H156Synthetic
    7H167Synthetic

    Regulatory and Health - Health and Safety Parameters and Guidelines

    Database Search

    List of unique identifiers to search the element in various chemical registry databases

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS1333-74-0
    RTECS NumberRTECSMW8900000
    CID Number CID783
    Gmelin Number-
    NSC Number-