# Whats in a BB?

In this lab we started out by massing 20mL of water in a 100mL graduated cylinder. We then added BBs until the meniscus went up to 25mL meaning we have 5mL of BBs. We then did 2 more trials and got 10, then 15mL of BBs. After each trial, we then massed the graduated cylinder on the 4 beam balance. After recording the mass and volumes, we were then able to determine the density of our BBs. Since we have 5, 10, and 15mL as our volumes, we must only write the density to the ones place because it was the number in our data with the least amount of significant digits. According to that, our densities were 8, 8, and 8. Looking at our previously researched densities of common metals, I noticed that there was a numerous range of densities from 7.87- 8.9 any of which could be a contributing metal to the BBs. Based on my data, I would have to conclude that the BB  consisted of iron with the density of 7.874 because it rounds the closest to my ‘precise’ density of 8. The density supports my conclusion because that is the closest possible answer and or outcome due to the 1 digit density I recorded. My data and calculations are precise because they are all similarly close together. As for accuracy, my data lacks it. Since its measurable data I couldn’t get exact numbers, but if I would have been more precise with my digits when measuring some of my data the results would have been closer to what an actual BB consists of. Densities are different because the equation is Mass/Volume. This means if two things have the same mass, but different volume (which most things do) their densities would differentiate because of that difference in volume.