1

If I have an array of 10 game objects and one of the game objects is deleted, leaving behind a missing game object for the element it was in, how do I detect what element contains a missing game object?

2

Video tutorial

http://unity3d.com/learn/tutorials/modules/beginner/scripting/if-statements

Read the if and loop section

http://forum.unity3d.com/threads/34015-Newbie-guide-to-Unity-Javascript-(long)

3

If you compare a GameObject with null after it’s destroyed it will return true (even though it’s not really null, it’s just the ‘==’ operator that is overloaded to provide this functionality).
Something like this should do the trick:

GameObject destroyedDude;
foreach(GameObject elem in myArray) {
    if(elem == null) {
        destroyedDude = elem;
    }
}