Question

which is unstable element in periodic table and why we call it unstable ?

Answer 1

heavy elements like Uranium, radium, nursery copper zinc , holmium terbium europium glad gold Platinum Osmium tungsten, these are the most unstable elements of the periodic table......... is having because of heavy atomic number and and orbits

Answer 2

All the element having atomic no greater then 92 are unstable due to weak inter nuclei force is too weak . Eg ,:- U , Np , Am , Cm , Md