Question

practice it! zoe and zj do an experiment to see which type of insulator keeps a cup of coffee hot the longest. which of the following would be a control group for this experiment? cup of tea empty cup cup of hot coffee with no insulator cup of hot coffee with no thermometer cup of hot coffee with no thermometer

Explanation:

In an experiment to test insulators for keeping coffee hot, the control group should have all the same conditions as the experimental groups except for the variable being tested (the insulator). A cup of hot coffee with no insulator provides a baseline to compare against cups with different insulators. A cup of tea is a different substance, an empty cup has no liquid to measure heat - retention for, and the presence or absence of a thermometer does not relate to the insulating property being tested.

Answer:

cup of hot coffee with no insulator