That kind of depends on exactly what you mean by "discovered". People have been using alloys containing nickel since prehistoric times, but it was only relatively recently (1751) that pure nickel was isolated and named.
NI, or Nickel, is placed on the period table of elements as atomic number 28. Nickel is an Element.
The Element Nickel: symbol Ni; at no 28; at wt 58.69; valence 2,3; melt 1455ºC; boil 2890ºC; density @25ºC 8.902 g/cc is a Transition Metal, discovered in 1751. Its oxide is basic in nature.
nickel
Yes, it is Nickel
The element Boron was discovered in Paris.
This chemical element is nickel.
Ni (and not NI) is the symbol for the element nickel.
The element niobium was discovered by Charles Hatchett in the year 1801. He discovered the element by analyzing a piece of columbite in a museum's collection.
It is an element (Ni). It can not be made.
Silver
There are many examples. Ni is a example element.
On the periodic table Ni represents the element Nickel.