Question

carlos set up three full vials beside one another and added drops to see the surface tensions of three different liquids. which event could be a source of error? a. the vials were different shapes. b. the air temperature varied when someone opened a window. c. the vials were made of the same material. d. the liquids that spilled over the edges could mix on the table.

Explanation:

Surface tension is affected by temperature. Variations in air - temperature due to opening a window can change the surface tension properties of the liquids, introducing an error in the experiment. Different vial shapes (A) are not a major source of error as long as they are full. Vials made of the same material (C) is a good control. Liquids spilling and mixing on the table (D) doesn't directly affect the surface - tension measurement in the vials.

Answer:

B. The air temperature varied when someone opened a window.