He Helium – Element Information, Facts, Properties, Trends,Uses, Comparison with other elements

2
He
Helium

Helium

Element 2 of Periodic table is Helium with atomic number 2, atomic weight 4.002602. Helium, symbol He, has a Face Centered Cubic structure and Colorless color. Helium is a noble gas element. Trivial name of Helium is noble gases*, aerogens. Know everything about Helium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.

2 He - Helium | SchoolMyKids

Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among all the elements.

How to Locate Helium 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 2 to find Helium 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 Helium on periodic table look for cross section of group 18 and period 1 in the modern periodic table.

Table of Contents

Helium History

The element Helium was discovered by Pierre Janssen in year 1895 in Sweden and United Kingdom . Helium derived its name from the Greek word helios, meaning 'sun'

Helium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Helium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

  Ppb by weight (1ppb =10^-7 %)
Abundance in Universe 0.23
Abundance in Sun 0.23
Abundance in Meteorites N/A
Abundance in Earth's Crust 5.5×10-7%
Abundance in Oceans 7.2×10-10%
Abundance in Humans N/A

Crystal Structure of Helium

The solid state structure of Helium is Face Centered Cubic.

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)

a b c
424.2 424.2 424.2 pm

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

alpha beta gamma
π/2 π/2 π/2

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 Fm_ 3m 2 He Helium - Crystal Structure | SchoolMyKids
Space Group Number 225
Crystal Structure Face Centered Cubic

Helium Atomic and Orbital Properties

Helium atoms have 2 electrons and the electronic shell structure is [2] with Atomic Term Symbol (Quantum Numbers) 1S0.

Atomic Number 2
Number of Electrons (with no charge) 2
Number of Protons 2
Mass Number 4
Number of Neutrons 2
Shell structure (Electrons per energy level) [2]
Electron Configuration 1s2
Valence Electrons 1s2
Oxidation State
Atomic Term Symbol (Quantum Numbers) 1S0

Shell Structure of Helium - Electrons per energy level

2 He Helium - Electron Shell Structure | SchoolMyKids
n s p d f
1 K 2

Ground State Electronic Configuration of Helium - neutral Helium atom

The ground state electronic configuration of Neutral Helium atom is 1s2. The portion of Helium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as 1s2]. 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 1s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Helium

Complete ground state electronic configuration for the Helium atom, Unabbreviated electronic configuration

1s2

Atomic Structure of Helium

Helium atomic radius is 31 pm, while it's covalent radius is 32 pm.

Atomic Radius

31 pm (0.31 Å)

Atomic Volume 22.4235406162 cm3
Covalent Radius 32 pm (0.32 Å)
Van der Waals Radius 140 pm
Neutron Cross Section 0.007 σa/barns

Atomic Spectrum of Helium

Atomic Spectrum of Helium | SchoolMyKids

Helium Chemical Properties: Helium Ionization Energies and electron affinity

The electron affinity of Helium is 0 kJ/mol

Valence 0
Electronegativity N/A
ElectronAffinity 0 kJ/mol

Ionization Energy of Helium

Refer to table below for Ionization energies of Helium

Ionization energy number Enthalpy - kJ/mol
1 2372.3
2 5250.5

Helium Physical Properties

Refer to below table for Helium Physical Properties

Density 0.1785 g/l
Molar Volume 22.4235406162 cm3

Elastic Properties

Young Modulus N/A
Shear Modulus N/A
Bulk Modulus N/A
Poisson Ratio N/A

Hardness of Helium - Tests to Measure of Hardness of Element

Mohs Hardness N/A
Vickers Hardness N/A
Brinell Hardness N/A

Helium Electrical Properties

Helium is N/A of electricity. Refer to table below for the Electrical properties of Helium

Electrical Conductivity N/A
Resistivity N/A
Superconducting Point N/A

Helium Heat and Conduction Properties

Thermal Conductivity 0.1513 W/(m K)
Thermal Expansion N/A

Helium Magnetic Properties

Magnetic Type Diamagnetic
Curie Point N/A
Mass Magnetic Susceptibility -5.9×10-9
Molar Magnetic Susceptibility -2.36×10-11
Volume Magnetic Susceptibility -1.05×10-9

Optical Properties of Helium

Refractive Index 1.000035

Acoustic Properties of Helium

Speed of Sound 970 m/s

Helium Thermal Properties - Enthalpies and thermodynamics

Refer to table below for Thermal properties of Helium

Melting Point N/A (N/A)
Boiling Point 4.22 K (-268.93 °C)
Critical Temperature 5.19 K
Superconducting Point N/A

Enthalpies of Helium

Heat of Fusion 0.02 kJ/mol
Heat of Vaporization 0.083 kJ/mol
Heat of Combustion N/A

Helium Isotopes - Nuclear Properties of Helium

Isotopes of rhodium. Naturally occurring Helium has 2 stable isotope - 3He, 4He.

Isotope Isotope Mass % Abundance T half Decay Mode
3He   0.000137%, Stable N/A
4He   Stable N/A
5He  
6He  
7He  
8He  
9He  
10He  

Regulatory and Health - Health and Safety Parameters and Guidelines

CAS Number CAS7440-59-7
RTECS Number RTECSMH6520000
DOT Hazard Class 2.2
DOT Numbers 1963
EU Number N/A
NFPA Fire Rating 0
NFPA Hazards N/A
NFPA Health Rating 1
NFPA Reactivity Rating 0
Autoignition Point N/A
Flashpoint N/A

Database Search

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

Database Identifier number
CAS Number - Chemical Abstracts Service (CAS) CAS7440-59-7
CID Number CID23987
Gmelin Number N/A
NSC Number N/A
RTECS Number RTECSMH6520000

List of Elements
1 H - Hydrogen
2 He - Helium
3 Li - Lithium
4 Be - Beryllium
5 B - Boron
6 C - Carbon
7 N - Nitrogen
8 O - Oxygen
9 F - Fluorine
10 Ne - Neon
11 Na - Sodium
12 Mg - Magnesium
13 Al - Aluminium
14 Si - Silicon
15 P - Phosphorus
16 S - Sulfur
17 Cl - Chlorine
18 Ar - Argon
19 K - Potassium
20 Ca - Calcium
21 Sc - Scandium
22 Ti - Titanium
23 V - Vanadium
24 Cr - Chromium
25 Mn - Manganese
26 Fe - Iron
27 Co - Cobalt
28 Ni - Nickel
29 Cu - Copper
30 Zn - Zinc
31 Ga - Gallium
32 Ge - Germanium
33 As - Arsenic
34 Se - Selenium
35 Br - Bromine
36 Kr - Krypton
37 Rb - Rubidium
38 Sr - Strontium
39 Y - Yttrium
40 Zr - Zirconium
41 Nb - Niobium
42 Mo - Molybdenum
43 Tc - Technetium
44 Ru - Ruthenium
45 Rh - Rhodium
46 Pd - Palladium
47 Ag - Silver
48 Cd - Cadmium
49 In - Indium
50 Sn - Tin
51 Sb - Antimony
52 Te - Tellurium
53 I - Iodine
54 Xe - Xenon
55 Cs - Cesium
56 Ba - Barium
57 La - Lanthanum
58 Ce - Cerium
59 Pr - Praseodymium
60 Nd - Neodymium
61 Pm - Promethium
62 Sm - Samarium
63 Eu - Europium
64 Gd - Gadolinium
65 Tb - Terbium
66 Dy - Dysprosium
67 Ho - Holmium
68 Er - Erbium
69 Tm - Thulium
70 Yb - Ytterbium
71 Lu - Lutetium
72 Hf - Hafnium
73 Ta - Tantalum
74 W - Tungsten
75 Re - Rhenium
76 Os - Osmium
77 Ir - Iridium
78 Pt - Platinum
79 Au - Gold
80 Hg - Mercury
81 Tl - Thallium
82 Pb - Lead
83 Bi - Bismuth
84 Po - Polonium
85 At - Astatine
86 Rn - Radon
87 Fr - Francium
88 Ra - Radium
89 Ac - Actinium
90 Th - Thorium
91 Pa - Protactinium
92 U - Uranium
93 Np - Neptunium
94 Pu - Plutonium
95 Am - Americium
96 Cm - Curium
97 Bk - Berkelium
98 Cf - Californium
99 Es - Einsteinium
100 Fm - Fermium
101 Md - Mendelevium
102 No - Nobelium
103 Lr - Lawrencium
104 Rf - Rutherfordium
105 Db - Dubnium
106 Sg - Seaborgium
107 Bh - Bohrium
108 Hs - Hassium
109 Mt - Meitnerium
110 Ds - Darmstadtium
111 Rg - Roentgenium
112 Cn - Copernicium
113 Nh - Nihonium
114 Fl - Flerovium
115 Mc - Moscovium
116 Lv - Livermorium
117 Ts - Tennessine
118 Og - Oganesson
Metalloid
Nonmetals
Other Nonmetals
Halogens Noble Gas
Metals
Alkali Metals Alkaline Earth Metals
Transition Metals Post-Transition Metals
Lanthanide Actinide