Katie's Reflections - School District of Shell Lake

Katie's Reflections

Chapter 1 Reflection: Poison Article (What’s the World’s Deadliest Poison?)

This was the first assignment we had in this class. It contained a lot of information that was very interesting, such as what LD50 means. It stands for Lethal Dose 50%. LD50 would be the amount of substance needed to kill 50% of a given population. LD100 would be the amount needed to kill the entire population.

Chapter 2 Reflection: Uncertainty in Measurement Activity

I went into this activity believing that I knew how to measure things correctly. I was wrong. I learned that with a measuring device, it can only measure to a certain accuracy, and from there, you have to guess the next digit. For example, for a length of yarn that is between 2.5 and 2.6 cm long, you guess the next digit, maybe 2.56, and record it like that.

Chapter 3 Reflection: Pg. 65, problems 6-9

We had to, using the Law of Conservation of Mass, figure out unknown values. For example, if given the mass of the input(s) of a chemical reaction, when given one of the two masses of the outputs, we had to find the mass of the other output. Like if 200g of one substance went in and two substances came out, one of which weighed 50g, how much did the other substance weigh? 150g. A few of them were a little tricky at first, but they got really easy the more of them that we did.

Labs: Lab #1: Unleashing the Scientific Method

In this lab, we had to mix a bunch of chemicals together, and we had to figure out how to do a lot of it ourselves. It was pretty interesting, and I learned that it’s a pretty good idea to follow the directions as closely as possible.

Your Choice: in Chapter 2: Chapter 2 Study Guide

I usually do the study guides the first day or two that we have them to get them out of the way. I started doing so with this, and I got to the dimensional analysis part and had no clue how to do it. Although, after a few tries, I was able to get that to convert, for example, 360 seconds into minutes, you would have to do:

360s/60sX1m+=6 minutes.

Chapter 4 Reflection on: Whiteboard Presentation Activity

I learned a lot from mine and others' boards. Like that Crookes invented the Cathode Ray Tube, but JJ Thompson was the one who used it to discover the electron.

Chapter 5 Reflection on: Chapter 5 Drawings

There are so many types of waves! This assignment helped me to know which ones are which. There's radio, AM, TV, FM, microwaves, infrared, visible light, ultra violet, X-rays, and gamma rays.

Chapter 6 Reflection on: Ch 6 Vocabulary

I knew there were Noble Gases and Halogens, but I only for sure knew what Noble Gases were. Looking at the definitions of those and other ones helped me learn other ones, like alkali metals, alkaliine earth metals, and others, and helped me increase my knowledge of the Periodic Table.

Labs Reflection on: Lab #4

This was a fun lab. I got to seperate a mixture, and do a chemical reaction! It was like two labs in one! I learned some of the ways to find if a chemical reation takes place, like if it gets hot or cold, or if new substances are formed.

Choose Your Own Reflection on: Lab #6

It's always fun when we get to burn things. In this lab, we made different colored flames and calculated theri energy based on their color. It was a little hard at times to tell, but for the most part we got the colors right. It was really suprising how much more energy the purples had compared to the reds. I guess peope had told me that before, but I think it's cooler and much easier to remember when you do it on your own.

Chapter 8 Reflection on: Determining Chemical Formulas

This packet was really helpful in figuring out chemical formulas from the chemical's name. All the cutting out the little pieces and gluing them back on was a little annoying, but it helped me see how the chemicals "fit" together. For each part of the compound they had different numbers of "teeth," delpending on how much of a charge it had. You had to arrange the different parts of the compound together so that all the teeth fit together and they made a nice triangle. It helped a lot, especially on those weird ones where something with a 2+ charge would pair with a 3- charge. There would end up being 3 of the 2+ and only two of the 3-.

Chapter 9 Reflection on: Chapter 9 Worksheets

With this assignment we learned how to draw Lewis Structures. They are pretty weird ad were hard to get the hang of doing at first. I did eventually get the hang of it, though, after we learned that we should write out all the atoms in it, their number of valence electrons, and the total number of pairs of electrons that should be in the structure. For exalmpe, here's what I would do with CH₄

C H H H H total number of electrons: 8 number of pairs: 4

Then, like in this one, if there is one different atom, that one usually goes in the middle and the other ones go around it.

H-C-H

And you put lines between them, signifying a bond (imagine there are lines between the carbon and the top and bottom hydrogens, like with the side ones). One line represents two electrons, one pair of them. So with lines between them all we have used all four pairs of the electrons that we had. So, that is the Lewis structure for CH₄, or methane.

Chapter 10 Reflection on: Chapter 10-1 Reactions & Equations- These were notes that we took in class about chemical formulas and equations. I knew a lot about balancing equations from 9th grade science last year, but I learned some of the pickier stuff, like using the delta symbol to show that heat was added, and that double arrows show that an equation is "reversible."

Labs Reflection on: Lab #8- I liked this lab a lot. We had a crossword puzzle! Also, my usual partner was gone, so i got to do the lab with Colleen! It was so fun! It was interesting, though, to see how elements reacted differently, even if they were in the same group. The farther down the periodic table the elements are, the less reactive they are.

Choose your own reflection on: Lab # 9- Ball and stick models are fun. I always got kind of scared looking at them because they looked so complicated, but they really aren't. In this lab we learned that all the little balls are the atoms, different colors represent the different ones, and the sticks connecting them are bonds. There can only be up to three of the bonds between two atoms.

Chapter 11 Reflection on: 11.3 Study Guide

This study guide helped me to learn about moles. It helped me count out all the atoms in molecules (which is REALLY important for BCA tables later…) and also helped me practice setting up the really picky problems that Lehn makes us do.

Chapter 12 Reflection on: 12.1 Study Guide

Before this Study Guide, I didn’t know what stoichiometry was. It’s actually the study of the quantitative relationships between the amounts of reactants used and the amounts of products formed by a chemical reaction. I also learned a little bit about how to use it to find out the ratios between the products and reactants.

Labs Reflection on: Lab # 10 (penny lab)

This lab was really fun. We got to mess with an acid and zinc and a Bunsen burner to change pennies different colors. And we got to keep them! It was pretty neat making the zinc bond to the copper and make an alloy which was silver. And when we heated it, I guess the zinc and copper mixed more and turned the penny a gold color. I liked this lab.

Choose your own reflection on: Mole Review Worksheet

This worksheet helped me to review moles and solidify my knowledge of the subject. It also helped me practice the annoying problems and do them the way Lehn kinda wanted me to, except I did them my own way. It also helped me practice finding the molar mass of different compounds.