Element 43 of Periodic table is Technetium with atomic number 43, atomic weight 98. Technetium, symbol Tc, has a Simple Hexagonal structure and Silver color. Technetium is a transition metal element. Know everything about Technetium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
Technetium (/tɛkˈniːʃiəm/) is a chemical element with symbol Tc and atomic number 43. It is the element with the lowest atomic number in the periodic table that has no stable isotopes:every form of it is radioactive. Nearly all technetium is produced synthetically, and only minute amounts are found in nature.
Read key information and facts about element Technetium
| Name | Technetium |
| Atomic Number | 43 |
| Atomic Symbol | Tc |
| Atomic Weight | 98 |
| Phase | Solid |
| Color | Silver |
| Classification | transition metal |
| Group in Periodic Table | 7 |
| Group Name | manganese family |
| Period in Periodic Table | 5 |
| Block in Periodic Table | d-block |
| Electronic Configuration | [Kr] 4d5 5s2 |
| Melting Point | 2157 °C |
| Boiling Point | 4265 °C |
| Electronic Shell Structure | [2, 8, 18, 13, 2] |
| CAS Number | CAS7440-26-8 |
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 43 to find Technetium 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 Technetium on periodic table look for cross section of group 7 and period 5 in the modern periodic table.
The element Technetium was discovered by Emilio Segrè in year 1937 in Italy . Technetium derived its name from the Greek tekhnètos meaning 'artificial'
The table below shows the abundance of Technetium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
| Ppb by weight (1ppb =10^-7 %) | |
|---|---|
| Abundance in Universe | N/A |
| Abundance in Sun | None |
| Abundance in Meteorites | None |
| Abundance in Earth's Crust | None |
| Abundance in Oceans | None |
| Abundance in Humans | None |
The solid state structure of Technetium 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.
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 |
|---|---|---|
| 273.5 | 273.5 | 438.8 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
| alpha | beta | gamma |
|---|---|---|
| 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 Name | P63/mmc |
|
| Space Group Number | 194 | |
| Crystal Structure | Simple Hexagonal |
Technetium atoms have 43 electrons and the electronic shell structure is [2, 8, 18, 13, 2] with Atomic Term Symbol (Quantum Numbers) 6S5/2.
| Atomic Number | 43 |
| Number of Electrons (with no charge) | 43 |
| Number of Protons | 43 |
| Mass Number | 98 |
| Number of Neutrons | 55 |
| Shell structure (Electrons per energy level) | [2, 8, 18, 13, 2] |
| Electron Configuration | [Kr] 4d5 5s2 |
| Valence Electrons | 4d5 5s2 |
| Oxidation State |
-3;-1
1;2;3;4;5;6;7 |
| Atomic Term Symbol (Quantum Numbers) | 6S5/2 |
Shell Structure of Technetium - Electrons per energy level
| n | s | p | d | f | |
|---|---|---|---|---|---|
| 1 | K | 2 | |||
| 2 | L | 2 | 6 | ||
| 3 | M | 2 | 6 | 10 | |
| 4 | N | 2 | 6 | 5 | |
| 5 | O | 2 |
The ground state electronic configuration of Neutral Technetium atom is [Kr] 4d5 5s2. The portion of Technetium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Kr]. 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 4d5 5s2, electrons in the outermost shell that determine the chemical properties of the element.
Complete ground state electronic configuration for the Technetium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d5 5s2
Technetium atomic radius is 183 pm, while it's covalent radius is 156 pm.
| Atomic Radius |
183 pm (1.83 Å) |
| Atomic Volume | 8.52173913043 cm3 |
| Covalent Radius | 156 pm (1.56 Å) |
| Van der Waals Radius | N/A |
| Neutron Cross Section | 22 σa/barns |
The electron affinity of Technetium is 53 kJ/mol
| Valence | 6 |
| Electronegativity | 1.9 |
| ElectronAffinity | 53 kJ/mol |
Refer to table below for Ionization energies of Technetium
| Ionization energy number | Enthalpy - kJ/mol |
|---|---|
| 1 | 702 |
| 2 | 1470 |
| 3 | 2850 |
Refer to below table for Technetium Physical Properties
| Density | 11.5 g/cm3 |
| Molar Volume | 8.52173913043 cm3 |
| Young Modulus | N/A |
| Shear Modulus | N/A |
| Bulk Modulus | N/A |
| Poisson Ratio | N/A |
| Mohs Hardness | N/A |
| Vickers Hardness | N/A |
| Brinell Hardness | N/A |
Technetium is Conductor of electricity. Refer to table below for the Electrical properties of Technetium
| Electrical Conductivity | 5×106 S/m |
| Resistivity | 2×10-7 m Ω |
| Superconducting Point | 7.8 |
| Thermal Conductivity | 51 W/(m K) |
| Thermal Expansion | N/A |
| Magnetic Type | Paramagnetic |
| Curie Point | N/A |
| Mass Magnetic Susceptibility | 3.42×10-8 |
| Molar Magnetic Susceptibility | 3.352×10-9 |
| Volume Magnetic Susceptibility | 0.0003933 |
| Refractive Index | N/A |
| Speed of Sound | N/A |
Refer to table below for Thermal properties of Technetium
| Melting Point | 2430 K (2157 °C) |
| Boiling Point | 4538 K (4265 °C) |
| Critical Temperature | N/A |
| Superconducting Point | 7.8 |
| Heat of Fusion | 23 kJ/mol |
| Heat of Vaporization | 550 kJ/mol |
| Heat of Combustion | N/A |
Isotopes of rhodium. Naturally occurring Technetium has 1 stable isotope - None.
| Isotope | Isotope Mass | % Abundance | T half | Decay Mode |
|---|---|---|---|---|
| 85Tc | ||||
| 86Tc | ||||
| 87Tc | ||||
| 88Tc | ||||
| 89Tc | ||||
| 90Tc | ||||
| 91Tc | ||||
| 92Tc | ||||
| 93Tc | ||||
| 94Tc | ||||
| 95Tc | ||||
| 96Tc | ||||
| 97Tc | ||||
| 98Tc | ||||
| 99Tc | ||||
| 100Tc | ||||
| 101Tc | ||||
| 102Tc | ||||
| 103Tc | ||||
| 104Tc | ||||
| 105Tc | ||||
| 106Tc | ||||
| 107Tc | ||||
| 108Tc | ||||
| 109Tc | ||||
| 110Tc | ||||
| 111Tc | ||||
| 112Tc | ||||
| 113Tc | ||||
| 114Tc | ||||
| 115Tc | ||||
| 116Tc | ||||
| 117Tc | ||||
| 118Tc |
| CAS Number | CAS7440-26-8 |
| RTECS Number | N/A |
| DOT Hazard Class | N/A |
| DOT Numbers | N/A |
| EU Number | N/A |
| NFPA Fire Rating | N/A |
| NFPA Hazards | N/A |
| NFPA Health Rating | N/A |
| NFPA Reactivity Rating | N/A |
| Autoignition Point | N/A |
| Flashpoint | N/A |
List of unique identifiers to search the element in various chemical registry databases
| Database | Identifier number |
|---|---|
| CAS Number - Chemical Abstracts Service (CAS) | CAS7440-26-8 |
| CID Number | N/A |
| Gmelin Number | N/A |
| NSC Number | N/A |
| RTECS Number | N/A |
Metalloid |
Nonmetals |
| Other Nonmetals | |
| Halogens | Noble Gas |
Metals |
|
| Alkali Metals | Alkaline Earth Metals |
| Transition Metals | Post-Transition Metals |
| Lanthanide | Actinide |