((infobox element
|symbol =Nb
|Z      =41
|number =41
|name   =niobium
|alt name=
|abundance=
|abundance in earth's crust=
|abundance in oceans=
|abundance in solar system=
|left=[[zirconium]]
|right=[[molybdenum]]
|above=[[vanadium|V]]
|below=[[tantalum|Ta]]
|image name=Niobium_crystals_and_1cm3_cube.jpg
|appearance=Gray metallic, bluish when oxidized
|electrons per shell=2, 8, 18, 12, 1
|phase=
|density=8.582&nbsp;g/cm<sup>3</sup><ref name="Arblaster 2018" />
|density conditions=(at&nbsp;20°&nbsp;C)
|density gpcm3nrt=
|melting point K=2750
|melting point C=2477
|melting point F=4491
|boiling point K=5017
|boiling point C=4744
|boiling point F=8571
|heat fusion=30
|heat vaporization=689.9
|heat capacity=24.60
|vapor pressure 1=2942
|vapor pressure 10=3207
|vapor pressure 100=3524
|vapor pressure 1 k=3910
|vapor pressure 10 k=4393
|vapor pressure 100 k=5013
|vapor pressure comment=
|crystal structure=cubic body-centered
|crystal structure Pearson symbol=cI2
|lattice constant=''a''&nbsp;=&nbsp;330.05&nbsp;pm (at&nbsp;20&nbsp;°C)<ref name="Arblaster 2018">((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))</ref>
|electronegativity=1.6
|number of ionization energies=3
|ionization energy 1=652.1
|ionization energy 2=1380
|ionization energy 3=2416
|atomic radius=146
|covalent radius=164±6
|magnetic ordering=paramagnetic
|electrical resistivity unit prefix=n
|electrical resistivity at 0=152
|thermal conductivity=53.7
|thermal expansion=<!-- see thermal expansion comment -->
|thermal expansion comment=((val|7.07|e=−6))/K (at&nbsp;20&nbsp;°C)<ref name="Arblaster 2018" />
|speed of sound rod at 20=3480
|magnetic susceptibility=
|magnetic susceptibility ref=
|Young's modulus=105
|Shear modulus=38
|Bulk modulus=170
|Poisson ratio=0.40
|Mohs hardness=6.0
|Vickers hardness=870–1320
|Brinell hardness=735–2450
|CAS number=7440-03-1
|naming=after [[Niobe]] in Greek mythology, daughter of [[Tantalus]] ([[tantalum]])
|discovered by=[[Charles Hatchett]]
|discovery date=1801
|first isolation by=[[Christian Wilhelm Blomstrand]]
|first isolation date=1864
|history comment label=Recognized as a distinct [[chemical element|element]] by
|history comment=[[Heinrich Rose]] (1844)
|QID=Q1046
))<!--

--><noinclude>
((Infobox element/element navigation|symbol=Nb))
((Template reference list))
((documentation|1=Template:Infobox element/doc))
</noinclude>