A homogeneous mixture or solid solution of two or more metals, the atoms of one replacing or occupying interstitial positions between the atoms of the other like :- Ni A silvery, hard, ductile, ferromagnetic metallic element used in alloys, in corrosion-resistant surfaces and batteries, and for electroplating. Atomic number 28; atomic weight 58.69; melting point 1,453°C; boiling point 2,732°C; specific gravity 8.902; valence 0, 1, 2, 3: