i am in a process of buying a website with revenue.........the seller has showed me screenshots and a check from google on his name..........how do i verify that the check he has been sent is for adsense OF THE WEBSITE HE IS SELLING.......thank you all

There is frankly no way of verification, anyone can use photoshop to edit. Adsense will never reveal such details to a third party, so it is mainly based on trust.