It depends on what the UI element is and in what context. If you're providing an element that normally has additional actions associated with it, by not having them readily present/visible the user will typically try to right-click/hover/etc. Once you establish that the right-click interaction exists on your application in one manner or another, the user will try it in other instances as well. That's basic recall.
If you want to see a good example of this, you can see that Gmail has a lot of right-click menus. They don't have a visual indication of the interaction either. You see that it works in one instance, subsequently driving you to attempt to use that particular interaction other instances. Take a look at the types of elements they utilize right-click for, as you will see a common theme in the type of menu items that accompanies them.