Measurement Quiz Reflection

I thought this first quiz was fairly simple, not bad at all. I'd stated in a previous blog post that I found significant figures pretty confusing, but after rereading the textbook and doing some online practice problems, I found myself getting the hang of it. One resource I found that was extremely helpful was Bozeman Science's video on significant figures. I enjoy watching his videos before any quiz/test as he is excellent at explaining scientific concepts.

One thing I had trouble on were the significant figure questions that included multiple operations. Since the problem would have both multiplication and addition, I was confused on whether to round the answer based on addition rules (lowest decimal) or multiplication rules (lowest number of sig figs). I wish we would've gone over this a bit more in class.

I am curious as to what we will be learning for the rest of the week. My plans for tonight are to work on the last meal project.

Recap of Signficant Figures Lesson

I'd never thought we'd be learning about the importance of zeroes, but today in class, I was proved wrong. The lesson covered how to round with decimals according to chemistry and how to identify significant figures. At first, I had no clue what was going on and was pretty overwhelmed by the amount of rules I needed to remember to accurately solve for answers. I think if I just go over the characteristics of a significant figure some more, I can probably grasp the hang of it. It'll just take some (a lot) of practice. This site contains some great practice problems. I hope we can also do some more in-class practice and review.

http://apchemcyhs.wikispaces.com/Uncertainty+and+Significant+Figures

Mole day is tomorrow!

Thoughts on the Measurement Pre-Test

While taking today's pretest on our new unit on Measurement, I found myself being stumped by a majority of the questions. However, some of the questions could be directly answered simply by looking at the periodic table or calculating some simple math on the calculator. I am interested in this unit because from what it seems, much of the unit revolves around math, and for me personally, math is very straightforward and easy to understand. I'm curious to how the concept of moles will tie in with this unit and also what significant figures mean. A large portion of the test involved significant figures, and as I had no clue what they are nor how they work, I just used some basic rounding rules to calculate my answers. I don't think that was the correct way to identify signficant figures, so I am definitely interested in what they are.

http://softpmomarketing.appspot.com/enterprise_project_performance.html

BTW, I am very much looking forward to Mole Day! (food... nice...)

Aspirin Lab

Today, the Wednesday groups took their pre-lab quiz. The quiz took a long time to complete, and I ran out of time trying to finish writing the steps of the lab. I regret choosing to do the lab today, rather than on Monday, because the questions on Monday were more simple and short. I hope all the aspirin made from Monday turns out well! 

http://www.health.harvard.edu/blog/taking-aspirin-linked-to-lower-risk-of-colorectal-cancer-201307166473

Final Thoughts on Unit 2: Atomic Structure & Radioactivity

Looking back on this unit, I believe we learned some fairly simple concepts that furthured our knowledge on atomic structure and how atoms react over time. We first learned about the different scientists and what they contributed to our knowledge on atomic structure. Dalton created basic postulates that characterized atoms. JJ Thompson experimented with a cathode ray and discovered the electron. He created a plum pudding model where all the electrons are placed equally apart from one another inside of an atom. Ernest Rutherford performed a gold foil experiment and discovered the proton and neutron, creating a model that had a dense center of positively charged protons and neutrally charged neutrons surround by orbiting electrons. In this unit, we also learned about calculating average atomic mass which was pretty easy; you just needed to double check that the input on the calculator was correct so you get the correct number. For Chapter 19, we began discussing the various types of radioactive decay and the impact it has on an atom's nucleus. Alpha, beta, and gamma were some of the most significant types. Additionally, half-life was another concept we learned. Half life is the time it takes for half of the original sample to decay. I thought this was the hardest concept for me personally since each half life problem would be worded differentlly, and I had trouble figuring out what steps to do to figure them out. However, with some more practice, I'll be able to get half life perfectly! The last thing, we did not learn in class but was also on the test, was nuclear fission & fusion. I wish we would've talked about this in class as it is a pretty interesting topic to discuss. However, this was also a pretty easy concept to understand: fission is neutrons disbanding to form lighter elements and fusion is neutrons joining to create a heavier element.

https://simple.wikipedia.org/wiki/Atom

I walked in today for the unit test feeling very anxious and frazzled. However, once I sat down and took the test, I was feeling pretty good about it. Even the half life problems were not that difficult. Overall, this unit was pretty interesting and I enjoyed the star log project that went along with it.