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.
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.
Read key information and facts about element Helium
Explore our interactive periodic table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of
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.
Interactive Periodic Table to Understand
and Learn Cool Trends
The element Helium was discovered by Pierre Janssen in year
1895 in Sweden and United Kingdom
derived its name from the Greek word helios, meaning 'sun'
The table below shows the abundance of Helium in Universe, Sun, Meteorites,
Earth's Crust, Oceans and Human Body.
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
dimensional space to form the structure.
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell
Lattice Constants (a, b and c)
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.
Helium atoms have 2 electrons and
the electronic shell structure is  with Atomic Term Symbol (Quantum Numbers) 1S0.
Shell Structure of Helium - Electrons per energy
The ground state electronic configuration of Neutral Helium atom is
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.
Complete ground state electronic configuration for the Helium atom, Unabbreviated electronic configuration
Helium atomic radius is 31 pm, while it's covalent radius is 32 pm.
The electron affinity of Helium is 0 kJ/mol
Refer to table below for Ionization energies of Helium
Refer to below table for Helium Physical Properties
Helium is N/A of electricity. Refer to
below for the Electrical properties of Helium
Refer to table below for Thermal properties of Helium
Isotopes of rhodium. Naturally occurring Helium has
2 stable isotope -
List of unique identifiers to search the element in various chemical registry databases