Nickel is magnetic.
Magnetic metals typically have unpaired electrons. Nickel contains unpaired electrons in its outer shell making it magnetic.
Nickel is categorized under ferromagnetic metals meaning it is highly magnetic and can also be turned into a magnet with its magnetic field. Nickel has a curie point of 355°C if subjected to temperatures above this point. Nickel loses its magnetism.

Magnetic properties of nickel
There are three different types of magnetism displayed by metals that are both magnetic and non-magnetic. Ferromagnetism, diamagnetism and Paramagnetism.
The magnetic properties of a metal are the key determinants of the type of magnetism the metal will display. Nickel displays ferromagnetism as well as Paramagnetism when it loses its magnetism.
Ferromagnetic metals contain atoms whose magnetic strength and orientation line up in the same direction making a strong magnetic field. These metals contain unpaired atoms which makes them strongly magnetic. Ferromagnetic metals can still maintain their magnetic polarization even in the absence of a magnetic field.

When nickel is exposed to temperatures above its curie point it loses its magnetism. The exposed nickel then displays Paramagnetism.
Paramagnetic metals function in principle opposite to the Diamagnetic metals. When subjected to a magnetic field, the metal atoms align in a similar direction to the field. This reaction leads to a weak attraction.
Diamagnetic metals have a weak repulsion when brought close to a magnetic field. When exposed to a magnetic field each atom aligns itself in the opposite direction.
Can Nickel become a Magnet?
Nickel can be magnetized into becoming a permanent magnet. Nickel is a ferromagnetic metal and one of its properties is the ability to retain magnetism even after the magnetic field has been withdrawn.
When Nickel is subject to a magnetic field the magnetic moment in its atoms aligns the moments in the field allowing it to retain the magnetism.