Element 34 of Periodic table is Selenium with atomic number 34, atomic weight 78.96. Selenium, symbol Se, has a Simple Monoclinic structure and Gray color. Selenium is a other nonmetal element. Trivial name of Selenium is chalcogens*. Know everything about Selenium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between those of its periodic table column-adjacent chalcogen elements sulfur and tellurium. It rarely occurs in its elemental state in nature, or as pure ore compounds.
Read key information and facts about element Selenium
Explore our interactive 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 34 to find Selenium 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 Selenium on periodic table look for cross section of group 16 and period 4 in the modern periodic table.
Explore Interactive Periodic Table to Understand and Learn Cool Trends
The element Selenium was discovered by Jöns Jakob Berzelius in year 1817 in Sweden . Selenium derived its name from the Greek selene, meaning 'moon'
The table below shows the abundance of Selenium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
The solid state structure of Selenium is Simple Monoclinic.
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)
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.
Selenium atoms have 34 electrons and the electronic shell structure is [2, 8, 18, 6] with Atomic Term Symbol (Quantum Numbers) 3P2.
Shell Structure of Selenium - Electrons per energy level
The ground state electronic configuration of Neutral Selenium atom is [Ar] 3d10 4s2 4p4. The portion of Selenium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ar]. 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 3d10 4s2 4p4, electrons in the outermost shell that determine the chemical properties of the element.
Complete ground state electronic configuration for the Selenium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4
Selenium atomic radius is 103 pm, while it's covalent radius is 116 pm.
103 pm (1.03 Å)
The electron affinity of Selenium is 195 kJ/mol
Refer to table below for Ionization energies of Selenium
Refer to below table for Selenium Physical Properties
Selenium is N/A of electricity. Refer to table below for the Electrical properties of Selenium
Refer to table below for Thermal properties of Selenium
Isotopes of rhodium. Naturally occurring Selenium has 5 stable isotope - 74Se, 76Se, 77Se, 78Se, 80Se.
List of unique identifiers to search the element in various chemical registry databases