Five groups of students in mr. walker's science class performed an experiment to determine the effect of salt on the boiling point of water. each group dissolved 5g of salt in 100ml of distilled water, heated the solution and recorded the boiling point with a thermometer that had divisions of 0.1â°c.

each group obtained exactly same boiling point for the salt solution, 100.8â°c. are the results valid?
a) no, because too little salt was used.
b)no, because it was not a controlled experiment.
c)yes, because each group obtained the same results.
d)yes, because the thermometer had divisions of 0.1â°c.

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a. one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b. one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c. one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.