It will also help me to know how to span the Chrome browser automatically on 2 monitors 

Spanning a window across multiple screens requires set up on the local computer (the respondent's). It isn't something you can control from the browser.
You could use CSS to have Qualtrics span the entire window width and a video within Qualtrics to span the entire width, but only people who already had their browser set up to span across screens would see it that way (i.e., almost nobody)

https://www.qualtrics.com/community/discussion/comment/29431#Comment_29431thank you so much for your respond
what if I use only my computer and get the people to do the survey in my computer in the lab - will it solve the problem?

what if I use only my computer and get the people to do the survey in my computer in the lab - will it solve the problem?

I will try! thank you so much! (: