What Makes Up Our World?
Science
Chemistry is an important sub-field in science. It is the study of the structure of substances and how different substances interact. Chemistry has potential to have a large impact on solving many problems in our day to day lives. An example is the use of chemistry to study drugs. Understanding the chemistry behind cancer drugs, by looking at the molecular structure of these drugs and how they can destroy cancerous cells, can help scientists cure this fatal disease. In science class, we based our curriculum off of the Chemistry IQWST book. We learned about the molecular structure of substances and how atoms break their bonds to create chemical reactions. I believe that my understanding of how atoms make up new substances and how to model atoms and molecules has improved.
I have a better understanding of what everything around me is made of. I realized how people make new substances by combining two current substances. In the future, I want to go into the field of medical science, for I see potential in this field of study. Chemistry could help us solve so many problems we face. Chemistry can allow us to analyze and observe the molecular changes due to diseases which can lead us to create treatments. We can see if these treatments actually work by seeing their effects on human beings and whether or not the person will get better with the treatment. Chemistry can help us do all of those things. By learning and understanding important concepts in chemistry, I can see if medical science is a good career choice for me. To further develop this skill for medicine, I will have to study more about molecular structures and investigate and analyze how drug molecules are created and how they interact with cells.
In Activity 7.0, page 54, we did a lab where we burned magnesium to create magnesium-oxide. On this page, you can see the ‘equation’ for this chemical reaction. When magnesium interacted with the oxygen in the air, there was a chemical reaction where magnesium-oxide was created. This chemical reaction occurred because there were two different substances that had two different chemical compositions. If you just cut the magnesium you would not get a chemical reaction. Melting point is the temperature at which a solid changes its state of matter to liquid. Mass is the amount of matter in a substance. Volume is the amount of space a substance takes up. While weight of an object is the amount of force that is exerted on an object, by earth. The reason for why this list of definitions for the terms is so important is that it explains how new substances are formed. Atoms explain to us how everything around is built up. Properties explain to us how to identify different substances from each other. Understanding different properties further explains how to identify different substances.
Over the unit, I learned many terms and concepts to get a better understanding of the topic. By learning these terms, first, I was able to follow along in class and really comprehend more complicated concepts. Atoms are what make up everything around us. Atoms are made up of protons, neutrons, and electrons. Electrons are particles that have negative electric charge. Electrons are critical in the formation of new substances because they help atoms rearrange and bond with other atoms. Properties are characteristics of a substance that makes the substance unique. Properties only change between substances. Properties cannot change if the same substances have a different volume and mass. An example of a property includes melting point and excludes mass and volume. The way that I understood this concept is illustrated by the following example. Let’s say that you have a piece of chalk. If you keep breaking the chalk into smaller and smaller pieces, and then look at its properties, the properties will not change. This is because you still have the same substance and the substance is still made of the same kind of atoms as before. The only thing that changed is the mass and the volume. On the other hand, if I added vinegar to one of the pieces of chalk, the chalk’s properties would change because it now has a different molecular composition since vinegar and chalk create a chemical reaction.
Modeling atoms and molecules allows us to be able to see what objects look like at the micro scale. In 6th grade, I modeled objects by drawing circles that just touched other circles. By studying how to accurately model atoms, we were able to learn more about how atoms bond together to make molecules and to see how each atom bonds with the next atom. In Activity 8.3 on page 74, we practiced drawing a molecule of acetic acid because we were analyzing the chemical reaction between copper and vinegar. Another key point to drawing a model is to create a key. We used three different colors to represent three different atoms (carbon, oxygen, and hydrogen) in the molecule of acetic acid. This step was to observe that atoms weren’t just circles that touched other circles. We were able to see how atoms connected with each other to form molecules. The reason for why I feel that I have grown in modeling atoms is that I modeled them for an educational purpose. By the models I made, I could really visualize how each molecule is made up of atoms. This was an improvement over my earlier model of slapping on a couple of circles together, to the current model of atoms bonded together to form molecules. I figured this out by learning an important factor in science class. I learned that atoms break at their bonds and rearrange with other atoms to form new substances. So, to make my models more accurate, I added lines that represented bonds, connecting the atoms. This was the first step to learning about atoms and molecules.
Activity 8.3, page 74
When modeling atoms, another question arose. Atoms seem to be connected, but how? I used to just draw circles and not realize how the atoms were constructed to make molecules that made up the substance. In Activity 8.3, page 75, you will see the molecule of copper acetate. Atoms are bonded together. When a new substance is made, the bonds break and the atoms rearrange with other atoms to create a new substance. When atoms go in search of a new ‘partner’ the atoms have some criteria to meet. When rearranging, the atom can gain and lose an electron to other atoms. Here is an easier way to think about this. Let’s say that Atom A is dancing with Atom B (Substance E) and Atom C is dancing with Atom D (Substance F). Atom A wants to dance with Atom C instead, so, Atom A detaches from Atom B and connects with Atom C (Substance G). Atom D then connects with Atom B (Substance H). Their chemical composition has changed since each atom has found a new partner to be with. So, new substances have been made. The reactants, or the two substances that I started out with, were Substance E and Substance F. The products are the end ‘results’ of the chemical reaction. The products of this reaction were Substance G and Substance H.
This page shows the most growth with this idea because I saw how acetic acid molecules bonded together. When copper was added into the system, the copper atom bonded to the acetic acid. You can see this with the added blue dot in between the two acetic acid molecules. Atoms also share electrons which creates this bond between them, to form molecules. This is evidence for my growth because when modeling these atoms, I saw which atoms bonded with each other and I saw how ‘new’ atoms were added to the current structure. Before, I didn’t understand how atoms created their iconic structures and I didn’t see how the atoms bonded together. Now I understand this idea.
Before I came to 7th grade, I didn’t understand how combining two substances could create a new substance. For all I knew, it could have been plain magic. Properties enable us to figure out if we made a new substance or not. Different substances have different properties. Before we started conducting labs, we learned about properties. Activity 8.2, page 66, you can see data collected about the properties of the same substance, before and after the experiment. The purpose of the lab was to study if acid rain can make a new substance when it comes in contact with copper. This page shows growth because I was able to identify the changes in properties of the two substances. I knew if I made a new substance or not when I conducted labs. By knowing this, I was able to really understand how atoms can create new substances. Though I was looking at this chemical reaction from the macro-scale, I still acquired more evidence about how a new substance can be formed. I also know how substances are made and what makes each of them so different. This is evidence for my growth because it shows my understanding of properties. This chart that you see on page 66 is a chart that documents observations that I observed about the properties of the copper penny, before and after the experiment. After seeing the change in properties of the copper penny, I knew that a new substance was made. If I did this experiment in the start of the year, I might only have observed that there was a new green layer on the penny and I wouldn’t have stopped to ask ‘why’. Now I know that color is a property that can be used to figure out if you made a new substance or not. I also learned about the other properties that you can test to observe if you made a new substance or not.
Activity 8.2, page 66
Activity 8.3, page 75
Activity 8.3, page 74
Activity 7.0, page 54