Se Selenium – Element Information, Facts, Properties, Trends,Uses, Comparison with other elements

34
Se
Selenium

Selenium

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.

34 Se - Selenium | SchoolMyKids

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.

How to Locate Selenium 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 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.

Table of Contents

Selenium History

The element Selenium was discovered by Jöns Jakob Berzelius in year 1817 in Sweden . Selenium derived its name from the Greek selene, meaning 'moon'

Selenium Presence: Abundance in Nature and Around Us

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

  Ppb by weight (1ppb =10^-7 %)
Abundance in Universe 3×10-6%
Abundance in Sun N/A
Abundance in Meteorites 1.3e-05
Abundance in Earth's Crust 5×10-6%
Abundance in Oceans 4.5×10-8%
Abundance in Humans 5×10-6%

Crystal Structure of Selenium

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.

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
905.4 908.3 1160.1 pm

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

alpha beta gamma
π/2 1.58493 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 P121/c1 34 Se Selenium - Crystal Structure | SchoolMyKids
Space Group Number 14
Crystal Structure Simple Monoclinic

Selenium Atomic and Orbital Properties

Selenium atoms have 34 electrons and the electronic shell structure is [2, 8, 18, 6] with Atomic Term Symbol (Quantum Numbers) 3P2.

Atomic Number 34
Number of Electrons (with no charge) 34
Number of Protons 34
Mass Number 79
Number of Neutrons 45
Shell structure (Electrons per energy level) [2, 8, 18, 6]
Electron Configuration [Ar] 3d10 4s2 4p4
Valence Electrons 4s2 4p4
Oxidation State -2;-1
1;2;3;4;5;6
Atomic Term Symbol (Quantum Numbers) 3P2

Shell Structure of Selenium - Electrons per energy level

34 Se Selenium - Electron Shell Structure | SchoolMyKids
n s p d f
1 K 2
2 L 2 6
3 M 2 6 10
4 N 2 4

Ground State Electronic Configuration of Selenium - neutral Selenium atom

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.

Unabbreviated electronic configuration of neutral Selenium

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

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4

Atomic Structure of Selenium

Selenium atomic radius is 103 pm, while it's covalent radius is 116 pm.

Atomic Radius

103 pm (1.03 Å)

Atomic Volume 16.3851421457 cm3
Covalent Radius 116 pm (1.16 Å)
Van der Waals Radius 190 pm
Neutron Cross Section 11.7 σa/barns

Atomic Spectrum of Selenium

Atomic Spectrum of Selenium | SchoolMyKids

Selenium Chemical Properties: Selenium Ionization Energies and electron affinity

The electron affinity of Selenium is 195 kJ/mol

Valence 6
Electronegativity 2.55
ElectronAffinity 195 kJ/mol

Ionization Energy of Selenium

Refer to table below for Ionization energies of Selenium

Ionization energy number Enthalpy - kJ/mol
1 941
2 2045
3 2973.7
4 4144
5 6590
6 7880
7 14990

Selenium Physical Properties

Refer to below table for Selenium Physical Properties

Density 4.819 g/cm3
Molar Volume 16.3851421457 cm3

Elastic Properties

Young Modulus 10 GPa
Shear Modulus 3.7 GPa
Bulk Modulus 8.3 GPa
Poisson Ratio 0.33

Hardness of Selenium - Tests to Measure of Hardness of Element

Mohs Hardness 2 MPa
Vickers Hardness N/A
Brinell Hardness 736 MPa

Selenium Electrical Properties

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

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

Selenium Heat and Conduction Properties

Thermal Conductivity 0.52 W/(m K)
Thermal Expansion N/A

Selenium Magnetic Properties

Magnetic Type Diamagnetic
Curie Point N/A
Mass Magnetic Susceptibility -4×10-9
Molar Magnetic Susceptibility -3.16×10-10
Volume Magnetic Susceptibility -1.93e-05

Optical Properties of Selenium

Refractive Index 1.000895

Acoustic Properties of Selenium

Speed of Sound 3350 m/s

Selenium Thermal Properties - Enthalpies and thermodynamics

Refer to table below for Thermal properties of Selenium

Melting Point 494 K (221 °C)
Boiling Point 958 K (685 °C)
Critical Temperature 1766 K
Superconducting Point N/A

Enthalpies of Selenium

Heat of Fusion 5.4 kJ/mol
Heat of Vaporization 26 kJ/mol
Heat of Combustion {"N/A", "N/A", "N/A"} J/(kg K)

Selenium Isotopes - Nuclear Properties of Selenium

Isotopes of rhodium. Naturally occurring Selenium has 5 stable isotope - 74Se, 76Se, 77Se, 78Se, 80Se.

Isotope Isotope Mass % Abundance T half Decay Mode
65Se  
66Se  
67Se  
68Se  
69Se  
70Se  
71Se  
72Se  
73Se  
74Se   0.89% Stable N/A
75Se  
76Se   9.37% Stable N/A
77Se   7.63% Stable N/A
78Se   23.77% Stable N/A
79Se  
80Se   49.61% Stable N/A
81Se  
82Se   8.73%
83Se  
84Se  
85Se  
86Se  
87Se  
88Se  
89Se  
90Se  
91Se  
92Se  
93Se  
94Se  

Regulatory and Health - Health and Safety Parameters and Guidelines

CAS Number CAS7782-49-2
RTECS Number {N/A, RTECSVS7700000, N/A}
DOT Hazard Class {N/A, 6.1, N/A}
DOT Numbers "N/A", {2658}, "N/A"
EU Number {N/A, N/A, N/A}
NFPA Fire Rating {N/A, 0, N/A}
NFPA Hazards N/ A, N/ A, N/ A
NFPA Health Rating {N/A, 2, N/A}
NFPA Reactivity Rating {N/A, 0, N/A}
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) CAS7782-49-2
CID Number {CID6326970, CID6326970, CID139346}
Gmelin Number {N/A, N/A, N/A}
NSC Number {N/A, N/A, N/A}
RTECS Number {N/A, RTECSVS7700000, N/A}

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