How to implement Notch Filter by Pole-Zero Placement?

I need to design and find the Transfer function of a Notch Filter using Pole-Zero displacement method with the following specs:

Notch Freq: 50Hz

Sampling Freq: 500Hz

I am really confused here, how does transfer function, PZ displacement method and these specs really add up? How are these related to each other?

If we use the iirnotch() function, to design this filter, I suppose we have to give Wo=50/500 (by taking a look at the description in “help iirnotch”).

And further I need to calculate the freq response of the filter for further processing.