Radon canister placement, condo

First time condo inspection coming up, mid/level floor. I know that there is a concern that granite countertops might emit radon gas. Just curious, if I am asked to do radon, where would the best place be to place the canister ? On top of the granite counter itself or further away. Thanks.

Protocol for testing in ANY residence is to avoid kitchens and bathrooms. Where did you get your Radon training?

Wow. Of course. Stupid question. Somehow , sitting at home overthinking the granite countertop issue sidetracked my thinking. Thanks for reminding me.