I'm guessing that you want to make an animaton of the spheres moving away from each other, and there's two ways to do this that I know of.
The first way is to separate them into two different objects by using 'p' and clicking 'Seperate by lose parts'. Then, animate then individually moving away from each other.
The second way would be to use shape keys. This method keeps them as a single object, but lets you animate them to move away from each other. To do this, go to the 'Shape key' tab.
Click the plus to add a shape key. It should automatically be named 'Basis'.
Move both spheres away from each other and thier starting locations in the 3d viewport.
Click the plus again to add another shape key for the object. This time, it should be called 'Key One'. If done correcly, dragging the slider will cause the spheres to move between thier starting point, 'Basis' and thier end point, 'Key 1'. Now, you can animate the position of the spheres using keyframes and the slider.