# 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.

# 3 Questions February 14th

This week we took a test, and also did a mini lab on measurements. I missed school on both Thursday and Friday due to school based activities. I missed a mini lab. Also this week our first glog was due. We are currently learning about chemical formulas and how to name them based on their formulas and vice versa. In the future I will try not to miss that much school, but I do not think that is likely because I will be missing this coming Friday again due to a tennis tournament. I will also try to turn in all my assignments on in time. I honestly think that labs help me understand the material the most because it is a hands on way of learning and it shows you how to do it right and the different effects that will happen if you do things out of order. The UT homework is very tedious, but it helps me realize how much I actually know about the topic at hand which is helpful and reassuring.

# Mini Lab Microscale

In our chemistry mini-lab today, we were basically mixing different chemicals together on a chart and recording their reactions. Some concluded with no observable reaction whereas others turned colors and some even produced precipitants. An example of a precipitant producing mixture was the NaOH and the AgNO. As we mixed these droplets together we noticed a brown clumping in the center of the droplets. As we blew it with air they formed more dense clumps and turned into a solid structure. Our next task on our list was to figure out the chemical name to each compound that we mixed. At first this was easy because it was cations first and then anions. The formulas began to become more complex as subscripts were added which tells you how many of each element there are. To have a correct formula the two ions must be equal which will make the entire thing equal. So if you are given Ag+ and Cl-, the formula would be AgCl because you have both a positive and a negative. The ions are denoted by the subscript tells how many of each element is needed for each other particular compound. In a formula the cation comes first and then the anion because that is a rule of the nomenclature. Patterns in nomenclature deal with the oxyanions. Due to the specific numbers of the element the suffixes will be different.

# Cobalt-60 SPICE AND FOOD RADIATION

In the case of Cobalt-60 the type of decay going on is Beta Decay. Which means the isotope is emitting an electron or positron.  An example of the equation is shown below.

Sources:

# Smaller Than an Atom

The model of the atom all begun with a man named John Dalton. HE had the first comprehensive theory of an atom. He stated that matter was composed of invisible particles. The model of this looked a lot like a marble. Following this model, a man named J.J.

Thomson found the negatively charged particle that science now knows as the electron. He found this through experimentation with charged rays. He fired electrical currents through pipes with gas in them. He notice when he recorded the mass that the mass was not changing. From there he concluded that in the pip contained electrically charged particles.

http://the-history-of-the-atom.wikispaces.com/J.J.+Thomson

Next, we had the fine discovery of the nucleus which is credited to Ernest Rutherford. He and colleagues shot alpha particles through a sheet of gold foil. By this the observation was that some of the particles went through, but some of them bounced back. They concluded that this heavy part that the particles could not pass through was the dense central part of the atom. Then they named it the nucleus. Next he splits the atom using alpha particles and nitrogen consequently causing him to discover the proton.

http://www.daviddarling.info/encyclopedia/R/Rutherfords_experiment_and_atomic_model.html

In conclusion the model of the atom was empirically developed because these scientists did not have the technology or the knowledge to see the small atom. Technology meaning they could not see it with a microscope or any means they had at their fingertips. They were ignorant to the fact that atoms contained all these individual particles so that is why they did not have to knowledge for discovering these things. Scientist went through blind experimentation, not knowing what they were going to discover, to develop every existent model of the atom. They did not see the atom they used rays, particles and their knowledge of physics to essentially come up with the idea of every individual particle of the atom and diagram what matter consists of. These aspects of the atom were discovered through observation considering they did not have the logic to discover them and that is why it is empirical.

Sources:

curiosity.discovery.com/question/discover-atoms

http://www.daviddarling.info/encyclopedia/R/Rutherfords_experiment_and_atomic_model.html

# Week of January 28-31

Recently in chemistry we have discussed radioactivity and classifications of matter. We took a test on Tuesday on the classification of matter unit which consisted of homogeneous and heterogeneous substances etc. Later this week we then had a mini lab on the rate of which our dear friend Frosty the Snowman melted. This taught us about the linear relationships of graphs and that data pools help scientists have more precise data collections and answers. We also did a lab about radioactivity and half lives that used the candy skittles. This helped me learn that you cannot predict the exact time an atom will decay but you can make an educated guess. Next the class is planning on going further into the study of radioactivity. I think this will be interesting because it will deal with the elements individual since no characteristics of these elements are the same.