Is the long side positive or negative? If you connect the negative terminal to the ground, the positive terminal is now at a potential of 1.
There are many checks we can do to see if a capacitor is functioning the way it should.
If a high voltage greater than rated is applied across capacitor, its dielectric strength will break down and eventually capacitor will explode.
What is surge voltage in terms of the tantalum capacitor? They contain big capacitors that can, potentially, kill you with the charge they contain.