If you like to assess your students using Google Forms and don't want students not in class to be able to view the assessment, this is the way to accomplish that. You can duplicate the form and change the specific word in the text box for each hour (if you like). Right before the students take the assessment, write the word on the board or give it orally. Once all students have completed the quiz, you can also change the password.
Here is a video giving complete instructions on how to do this.