No element has the symbol Nu.
Other symbols that might be mistaken for Nu include:
Na: Sodium
Ne: Neon
N: Nitrogen
A chemical element, or an element, is a material which cannot be broken down or changed into another substance using chemical means. Elements may be thought of as the basic chemical building blocks of matter. Depending on how much evidence you require to prove a new element has been created, there are 117 or 118 known elements.
Get interactive periodic table with element scarcity (SRI), discovery dates, melting and boiling points, group, block and period information at The Royal Society of Chemistry.