Editing Group 5 element (section)

== Occurrence ==

There are 160 parts per million of vanadium in the Earth's crust, making it the [[Abundance of elements in Earth's crust|19th most abundant element]]. [[Soil]] contains on average 100 parts per million of vanadium, and [[seawater]] contains 1.5 parts per billion of vanadium. A typical human contains 285 parts per billion of vanadium. Over 60 vanadium ores are known, including [[vanadinite]], [[patronite]], and [[carnotite]].<ref name = "Emsley">{{cite book|last=Emsley|first=John|title=Nature's Building Blocks|year=2011}}</ref> There are 20 parts per million of niobium in the Earth's crust, making it the 33rd most abundant element there. Soil contains on average 24 parts per million of niobium, and seawater contains 900 parts per [[Orders of magnitude (numbers)#1015|quadrillion]] of niobium. A typical human contains 21 parts per billion of niobium. Niobium is in the minerals [[columbite]] and [[pyrochlore]].<ref name = "Emsley"/> There are 2 parts per million of tantalum in the Earth's crust, making it the 51st most abundant element there. Soil contains on average 1 to 2 parts per billion of tantalum, and seawater contains 2 parts per trillion of tantalum. A typical human contains 2.9 parts per billion of tantalum. Tantalum is found in the minerals [[tantalite]] and pyrochlore.<ref name = "Emsley"/> Dubnium does not occur naturally in the Earth's crust, as it has no stable [[Isotope|isotopes]].<ref>{{cite book |last1=Münzenberg |first1=G. |title=Handbook of Nuclear Chemistry |last2=Gupta |first2=M. |publisher=Springer |year=2011 |page=877 |chapter=Production and Identification of Transactinide Elements |doi=10.1007/978-1-4419-0720-2_19}}</ref>