This is the 26th installment of the STEM Bell Ringers series (Science, Technology, Engineering,and Math), and it signifies a change. There are 20 open-ended questions for students. The answer key and references are included for the teachers and students who may struggle to recall or apply information (e.g., level one, Exceptional Ed, ESOL, etc), may click on embedded hyperlinks to assist them. This is a good activity for morning work, ticket out the door, test-prep, or homework.Topics covered