Answer:
The answer is - a cup of ice cubes to cool the water.
Step-by-step explanation:
The thing that is least likely to be a part of the experiment is - a cup of ice cubes to cool the water.
A burner to heat water and a beaker in which water is boiled. These are essential as warming water will result in generating vapor. And these vapors can be condensed on a cold glass plate, as water vapor condenses easily on cold surfaces.
So, the unusable thing here is - a cup of ice cubes to cool the water.
