If we are using chaining technique for collision resolution in hashing, then the minimum chain length will be 1 (not zero, since then there will be no chain). The maximum chain length will be Ο(n) since we can have all the elements in one slot. An example of this worst case could be: hash function h(k) = k mod 10 and the elements as 2,12, 22, 32, 42, 52, 62, 72, 82, 92
The average case would be an average of all the intermediate cases, (best case + worst case)/2 i.e., Ο(n).
This is the time complexity for the chaining element access.