State union of Serbia and Montenegro or simply Serbia and montenegro. In 2006. they separated thus creating two states: Serbia and Montenegro.

Serbia and Montenegro were formed when the Czech Republic was split.

There is no place called Serbia & Montenegro. Between 1998 and 2006 there was a country called Serbia & Montenegro but since 2006, when Montenegro declared independence, they have been 2 separate countries - Serbia and Montenegro. Postal codes depend on which city you are posting to.

Montenegro declared independance from serbia on 3. june 2006.

No, Montenegro and Serbia are two separated countries.