Science Assessment ~ Topics ~ Energy: Forms, Transformation, Transfer, and Conservation ~ Item EG051004 ~ Student Performance

A student has two glasses of water. Glass 1 and Glass 2 have the same number of water molecules in them.

If the average speed of the water molecules in Glass 1 is less than the average speed of the water molecules in Glass 2, which glass of water has less thermal energy?

The water in Glass 1 has less thermal energy.
The water in Glass 2 has less thermal energy.
The water in Glass 1 and the water in Glass 2 have the same amount of thermal energy.
The only way to tell which glass of water has less thermal energy is to also know the temperature of the water.

Distribution of responses
Answer Choice		Overall	Grades			Gender		Primary Language
		n = 3017	4–5 n = 0	6–8 n = 1498	9–12 n = 1519	Male n = 1402	Female n = 1539	English n = 2683	Other n = 240
A.	The water in Glass 1 has less thermal energy.	43%	N/A	38%	47%	43%	42%	44%	34%
B.	The water in Glass 2 has less thermal energy.	18%	N/A	19%	16%	19%	16%	18%	16%
C.	The water in Glass 1 and the water in Glass 2 have the same amount of thermal energy.	18%	N/A	20%	17%	16%	20%	17%	28%
D.	The only way to tell which glass of water has less thermal energy is to also know the temperature of the water.	22%	N/A	23%	20%	21%	22%	21%	23%

Science Assessment

Item EG051004: For two glasses containing the same number of water molecules, the water with molecules that are moving at the lower average speed has less thermal energy.