Measurement and DensityIntroductionIn this experiment, there were two main purposes: to practice measuring and identifying significant figures, and understanding the estimated uncertainty that applied to each instrument. To do this distilled water was measured into a 10-mL. graduated cylinder and then poured into a 25-mL. graduated cylinder measured and recorded to the estimated uncertainty of + .01-mL. Then the water was poured into a 100-mL. graduated cylinder and measured and recorded to the estimated uncertainty of + .1 mL. This process allowed for practice in reading the meniscus and finding estimated uncertainty. The second purpose of this experiment was to measure the masses and volumes of three unknown metals and then use those to calculate density. Masses were measured on an electric balance and volume was calculated using the amount of water displaced in a gradated cylinder by the unknown metal. The values were then used to calculate density, standard deviation, and percent error. Once the density was found themetals were able to be identified, then the accepted value was then used to calculate percent error. All of these calculations are important because they express how precise and accurate thedata collected is. This important because science needs to be repeatable and without practice there is a greater chance of measurement error in the laboratory. The whole experiment was good practice in accurate measurements and calculating data.Results and DiscussionDuring the first part of the lab, 10 mL. of water was measured in two-different sized graduated cylinders. This measurement test was done to understand the difference of major and minor scale division, as well as how to determine estimated uncertainty. It was noticed that in the 25-mL. graduated cylinder the data recorded was more accurate because it had a smaller minor scale of division. It was also noticed that the measurements of the same liquid varied significantly between the two graduated cylinders. A potentially error in this part of the experiment could be that not all of the water transferred from one cylinder to the next, this cause a slight skew in the estimated uncertainty. In the second part of the lab mass was measured by electric balances. The initial mass was measured and then the final mass was taken. These were used to calculated the masses of each metal (initial mass- final mass= mass of metal). Then volume was measure by the water displacement once the metal has been added to the original 7 mL. of water. Metal A had massesof: 7.0849g., 7.0127g., and 6.773 g. and the volumes of metal A were all 1.00mL. The determined densities for each trial of metal A, the results were: 7.0849g./mL., 7.0127g./mL., and 6.773 g/mL, averaging out at 6.957g./mL. Metal A was determined to be tin (Sn). Metal B has masses of: 10.493g., 11.158g., and 10.788g. and the volumes of metal B were 1.00 mL. The calculated densities for metal B were: 10.493g./ mL., 11.158g./mL., and 10.788g/mL. With metalB having an average 10.813g./mL. it was determined to be lead because the accepted value of lead is 11.35g/mL. Metal C had the masses of: 1.937 g., 1.929g., and 2.204g, with the volume of 1.00mL for all trials. The calculated densities of metal C were: 1.937 g./mL., 1.929g./mL., and 2.204g/mL. averaging out to have a density of 2.023g./mL. Metal C was determined to be Siliconbecause it has an accepted density of 2.3296g./mL. During the second part of the lab a few errors could have been made, one being that the volume of each metal might not have been 1.00 exactly. This could change the densities of each metal because maybe too much or not enough metal was added to the graduated cylinder skewing the final mass. A second error that could have occurred is when weighing the metals onthe balances, different balances were used. This could skew the data because they had differentdecimals of estimated uncertainty. The last step of this lab was to calculate percent error in the accumulated data. To do this you subtract the measured value by the accepted value then divide that by the accepted value and multiply by 100 to find the percentage. For the tin (metal A) the percent error was the lowest at 4.117%, Lead (metal B) had a 4.73% error, and silicon (metal C) had the highest percent error at13.16%. This could be a result of the silicon being the least dense material measured in this experiment. This experiment was very useful learning how to accurately measure mass and volume in the lab as well familiarizing one’s self with calculating density, standard deviation, and percent