Text Entry Box issue when user includes a blank space

Hello all, I'm having an issue with my students whereby they are in the habit of clicking on the space bar at the end of words...which is causing them to get the answers wrong.  As seen in my slide below

The answer is "bromine trioxide", however, it frequently occurs where my students type "bromie trioxide_" (where the underscore represents them clicking on the space bar prior to submitting the answer).  Is this a "bug" the program?  Do I have to add an additional answers with a blank spaces (this seems tedious and it would seem to me a common user error that should be ignored)?  Is there a setting somewhere?  Thanks in advance for any assistance.