Template:Infobox technetium

{{infobox element

|name =technetium

|symbol =Tc

|Z =43

|number =43

|mass number comment=(data not decisive){{efn|name="most stable isotope"|The most stable isotope of technetium cannot be determined based on existing data due to overlapping measurement uncertainties for the half-lives of the two longest-lived isotopes. The half-life of ⁹⁷Tc with an uncertainty corresponding to one standard deviation is {{val|4.21|0.16}} million years, while that for ⁹⁸Tc is {{val|4.2|0.3}} million years; these measurements have overlapping confidence intervals.{{NUBASE2020|ref}} }}

|abundance=

|abundance in earth's crust=

|abundance in oceans=

|abundance in solar system=

|left=molybdenum

|right=ruthenium

|above=Mn

|below=Re

|appearance=shiny gray metal

|image name=Technetium-sample-cropped.jpg

|electrons per shell=2, 8, 18, 13, 2

|phase=

|phase comment=

|density=⁹⁸Tc: 11.359 g/cm³
⁹⁹Tc: 11.475 g/cm³

|density conditions=(at 20° C)

|density gplstp=

|density gpcm3nrt=

|density gpcm3mp=

|melting point K=2430

|melting point C=2157

|melting point F=3915

|boiling point K=4538

|boiling point C=4265

|boiling point F=7709

|triple point K=

|triple point kPa=

|critical point K=

|critical point MPa=

|heat fusion=33.29

|heat vaporization=585.2

|heat capacity=24.27

|vapor pressure 1=2727

|vapor pressure 10=2998

|vapor pressure 100=3324

|vapor pressure 1 k=3726

|vapor pressure 10 k=4234

|vapor pressure 100 k=4894

|vapor pressure comment=(extrapolated)

|crystal structure=hexagonal close packed

|crystal structure Pearson symbol=hP2

|lattice constants=a = 274.12 pm
c = 439.90 pm (at 20 °C){{cite book |last=Arblaster |first= John W. |title=Selected Values of the Crystallographic Properties of Elements |publisher=ASM International |publication-place=Materials Park, Ohio |date=2018 |isbn=978-1-62708-155-9}}

|electronegativity=1.9

|number of ionization energies=3

|ionization energy 1=686.9{{cite journal |last1=Mattolat |first1=C. |last2=Gottwald |first2=T. |first3=S. |last3=Raeder |first4=S. |last4=Rothe |first5=F. |last5=Schwellnus |first6=K. |last6=Wendt |first7=P. |last7=Thörle-Pospiech |first8=N. |last8=Trautmann |date=24 May 2010 |title=Determination of the first ionization potential of technetium |url= |journal=Physical Review A |volume=81 |issue= |pages=052513 |doi=10.1103/PhysRevA.81.052513}}

|ionization energy 2=1470

|ionization energy 3=2850

|atomic radius=136

|atomic radius calculated=

|covalent radius=147±7

|Van der Waals radius=205

|magnetic ordering=Paramagnetic

|electrical resistivity unit prefix=n

|electrical resistivity at 0=

|electrical resistivity at 20=200

|thermal conductivity=50.6

|thermal conductivity 2=

|thermal diffusivity=

|thermal expansion=

|thermal expansion comment={{val|8.175|e=−6}}/K (at 20 °C)

|speed of sound=

|speed of sound rod at 20=16,200

|speed of sound rod at r.t.=

|magnetic susceptibility= {{val|+270.0|e=−6}}

|magnetic susceptibility ref= (298 K){{Cite book|title=CRC, Handbook of Chemistry and Physics|last=Weast|first=Robert|publisher=Chemical Rubber Company Publishing|year=1984|isbn=0-8493-0464-4|location=Boca Raton, Florida|pages=E110}}

|Young's modulus=

|Shear modulus=

|Bulk modulus=

|Poisson ratio=

|Mohs hardness=

|Vickers hardness=

|Brinell hardness=

|CAS number=7440-26-8

|naming=after Greek τεχνητός, 'artificial', for being the first artificially produced element

|predicted by=Dmitri Mendeleev

|prediction date=1871

|discovery and first isolation by=Emilio Segrè and Carlo Perrier

|discovery date=1937

|QID=Q1054

}}