Final answer:
In an empty list, there are no nodes, and both the head and tail references are null.
Step-by-step explanation:
In an empty list, there are no nodes. Nodes are the individual elements in a linked list that store data and have references to the next node in the list. Therefore, the number of nodes in an empty list is 0.
In an empty list, both the head and tail references will be null. The head reference points to the first node in the list (which is null in this case) and the tail reference points to the last node in the list (which is also null in the case of an empty list).