Question

During a biology lab practical, students were required to identify a metal by its density. All the metals were painted green so students could not use color as a factor to eliminate choices. Carl computed the density of his sample metal to be 8.9 g/cm3. Since Carl's lab grade depended on his accuracy and correct identification of the sample metal, he was unsure which sample he had, nickel or copper. What would you tell Carl about his density measurement? A) Disregard any decimal points and use only whole numbers. B) 8.9 is closer to to 8.91 than 8.96 so Carl should chose nickel. C) Re-do the measurements, several times, and take the average density before making a decision. D) When using water displacement to find the volume, be sure to read the meniscus to the nearest 0.01 ml.

Answer 1

Answer:

C) Re-do the measurements, several times, and take the average density before making a decision.

Explanation:

For the correct identification of the metal, weather its nickel or copper, Carl should repeat the experiment several times and take the average density before making the decision. It is important because it reduces the chance of error and ensure the data integrity.  The more the sample size is, lessen would be the error.  

Answer 2

Answer:

Re-do the measurements, several times, and take the average density before making a decision.

Explanation:

Do not rely on just one set of measurements if your grade depends on accuracy. Take several sets of measurements; next take an average. Do not round while measuring or before computing; round last.