In order to ease the stress on me, I've been relying on the American Chemical Society's lessons specifically designed to teach middle school students. These lessons are full of cheap, hands-on activities and the website provides animations to help the students visualize what's happening in the "land of particles". Unfortunately for me, I had a bad spell of teaching where my students developed a terrible image and emotion towards the class. Moreover, these activities aren't "dazzling" enough to change their views (or if they are changing, then I sure wish it would go faster!).
So, how can I hook-line-and-sinker my students? I was up late last night in awe during a day dreaming session of chemistry. The following ideas are what caused the late night excitement.
1. The incredible strength of chemical bonds
2. The fact we and everything else are "dancing" particles
3. Two "wrongs" DO make a right
4. Breaking particles is what fuels us (and we run on "rechargeable" batteries)
5. Water is the coolest substance ever
I will break down each of these in more depth to both further clarify the idea and help me figure out what experiences my students will need to have the true awe feeling.
The incredible strength of chemical bonds
I wanted to see how strong chemical bonds were by comparing them to something everyone has available to them: water. I asked my students to measure how fast they could pull a drop of water 5 inches. Most people are probably thinking, "Big whoopdee doo! It's only 5 inches!" But, what is 5 inches to an individual water molecule? I did the math and if water molecules were my size, traveling 5 inches is the equivalent to traveling across the United States about 220 times! So, what was the average time my students measured for pulling a drop of water 5 inches? It was 8.02 seconds. That makes the speed for a human sized water molecule 247,371,293 miles/hour, or 37% the speed of light.
Maybe you don't appreciate the comparison I just made (e.g. the mass difference would make it physically impossible to travel that fast). However, you can't deny the fact an individual water molecule traveled more than 600,000,000 times its length in around 8 seconds. You try to keep all of your body parts while traveling at those speeds!
Amazingly, the bonds holding water molecules together are considered weak! Imagine how strong the strong bonds are!
The fact we and everything else are "dancing" particles
Take a moment and cover your ears. What do you hear? You may want to say, "nothing," but there is a hum. Now take a moment and cover your eyes. What do you see? Again, you may want to say, "nothing," but tiny "stars" are always there. How come this happens? It happens because you never stop moving! Sound and sight occur because particles hit one another which sends a signal to the brain.
Let's try another experiment. The instructions are simple: listen to the song and pay attention to what your body "wants" to do.
At 20 seconds into the song, what did you notice? Then at 40 seconds into the song, what did you notice? I'm predicting your body increased its motion at both times. Why? The answer is actually simple. At those times the energy of the song increased. In the particle world, if you increase the energy of a particle, then it will speed up. We can feel this happen to ALL of our particles when we listen to music. Thus, we are nothing more than "dancing" particles! And to emphasize my point (and show this works for non-living things, too), check out Oobleck dancing on a speaker in the video below.
Two "wrongs" DO make a right
Chemistry gives us a natural example of this popular saying. Look at how two elements react if separate:
Sodium:
Chlorine:
Chlorine gas was one of the weapons used in World War I. When breathed, the gas causes acidic burns in the lungs until the lungs no longer function. Death by asphyxiation.
Now, put these two "wrongs" together: sodium + chlorine = table salt!
Nom nom nom. There's a reason I don't buy (many) salty snacks: I don't stop eating them! Salt is not only delicious, but it's required for life. Before moving on, I must make it clear I'm using salt colloquially, meaning referring to table salt. Table salt is composed of two elements: sodium and chlorine. These elements are vital to many systems in our body, such as the immune system, nervous system, and digestive system. What exactly does sodium and chlorine do for us?
Going back to the "nom nom nom", one thing chlorine helps in is digestion! Check out this video of a McDonald's burger being placed in hydrochloric acid, the acid in our stomach.
Without our stomach acid, we would not be able to digest proteins quickly. If you want to know what happens when one becomes protein deficient, look at all the sad save-a-child-in-Africa ads!
Chlorine also plays a major role in our immune system. Most people remember the immune system has something to do with the white blood cells. But how do they actually work? The same way bleach does! See if you can find the chlorine containing compound in bleach.
If you saw "hypochlorite", then you pick up quickly! The white blood cells produce the key ingredient found in bleach, which most people know is a disinfectant. So when you are sick, know your body is "bleachin'"!
What about sodium? Well, hopefully you don't take for granted moving! Sodium plays a very important role in allowing our muscles to move. I'm specifically talking about its role in the sodium-potassium pump. Below is a diagram of how the pump functions.
There are a some important things to note. First, sodium is represented by "Na+" and potassium is represented by "K+". Second, for every 3 sodiums that exit the cell, 2 potassiums enter. Third, the "+" indicates the particles are electrically charged. So in the case of moving, being able to control the charge of the cells is important so as to not have our muscles stuck in a contraction (or a cramp), or unable to contract. Thus, sodium is a key player in our ability to move (the pump also has other functions, but I think understanding the need for motion is universal)!
Breaking particles is what fuels us (and we run on "rechargeable" batteries)
Let's marvel at how much energy is stored in bonds. My friend and I wanted to think of a way for my students to understand the amount of energy and we came up with the following demonstration. First, you show one liter of gasoline and ask students how much energy they think is stored in it. Second, you take your students to a school bus with no gas in its tank and pour the liter of gas in the tank. Third, you take the students for a ride until the bus comes to a stop and tell the students to push the bus back to school. Think of the students' faces! In case you are wondering, we calculated the bus would travel just under 3 miles on 1 liter of gasoline.
All that work of moving the school bus was contained in the bonds of the gasoline. More amazingly, the breaking of those bonds, or the burning of the fuel, is how the energy was released! The same thing is happening inside of us. Look up at the diagram above of the sodium-potassium pump. The star shape with "ATP" inside of it powers the pump, and you'll notice the "ATP" turns into "ADP". This represents one phosphate group left, or broke off, which is where the energy for the pump came from. Furthermore, that "ADP" will find another phosphate group and recharge to be used again. How incredible is that? All this renewable energy talk while our our cells have been doing it for a very long time!
Water is the coolest substance ever
What does all known life have in common? Water. It's unavoidable! But what exactly makes water so incredible? Below you will find a list of reasons why I think it's amazing.
The incredible strength of chemical bonds
I wanted to see how strong chemical bonds were by comparing them to something everyone has available to them: water. I asked my students to measure how fast they could pull a drop of water 5 inches. Most people are probably thinking, "Big whoopdee doo! It's only 5 inches!" But, what is 5 inches to an individual water molecule? I did the math and if water molecules were my size, traveling 5 inches is the equivalent to traveling across the United States about 220 times! So, what was the average time my students measured for pulling a drop of water 5 inches? It was 8.02 seconds. That makes the speed for a human sized water molecule 247,371,293 miles/hour, or 37% the speed of light.
Maybe you don't appreciate the comparison I just made (e.g. the mass difference would make it physically impossible to travel that fast). However, you can't deny the fact an individual water molecule traveled more than 600,000,000 times its length in around 8 seconds. You try to keep all of your body parts while traveling at those speeds!
Amazingly, the bonds holding water molecules together are considered weak! Imagine how strong the strong bonds are!
The fact we and everything else are "dancing" particles
Take a moment and cover your ears. What do you hear? You may want to say, "nothing," but there is a hum. Now take a moment and cover your eyes. What do you see? Again, you may want to say, "nothing," but tiny "stars" are always there. How come this happens? It happens because you never stop moving! Sound and sight occur because particles hit one another which sends a signal to the brain.
Let's try another experiment. The instructions are simple: listen to the song and pay attention to what your body "wants" to do.
At 20 seconds into the song, what did you notice? Then at 40 seconds into the song, what did you notice? I'm predicting your body increased its motion at both times. Why? The answer is actually simple. At those times the energy of the song increased. In the particle world, if you increase the energy of a particle, then it will speed up. We can feel this happen to ALL of our particles when we listen to music. Thus, we are nothing more than "dancing" particles! And to emphasize my point (and show this works for non-living things, too), check out Oobleck dancing on a speaker in the video below.
Two "wrongs" DO make a right
Chemistry gives us a natural example of this popular saying. Look at how two elements react if separate:
Sodium:
Chlorine:
Chlorine gas was one of the weapons used in World War I. When breathed, the gas causes acidic burns in the lungs until the lungs no longer function. Death by asphyxiation.
Now, put these two "wrongs" together: sodium + chlorine = table salt!
Nom nom nom. There's a reason I don't buy (many) salty snacks: I don't stop eating them! Salt is not only delicious, but it's required for life. Before moving on, I must make it clear I'm using salt colloquially, meaning referring to table salt. Table salt is composed of two elements: sodium and chlorine. These elements are vital to many systems in our body, such as the immune system, nervous system, and digestive system. What exactly does sodium and chlorine do for us?
Going back to the "nom nom nom", one thing chlorine helps in is digestion! Check out this video of a McDonald's burger being placed in hydrochloric acid, the acid in our stomach.
Without our stomach acid, we would not be able to digest proteins quickly. If you want to know what happens when one becomes protein deficient, look at all the sad save-a-child-in-Africa ads!
Chlorine also plays a major role in our immune system. Most people remember the immune system has something to do with the white blood cells. But how do they actually work? The same way bleach does! See if you can find the chlorine containing compound in bleach.
What about sodium? Well, hopefully you don't take for granted moving! Sodium plays a very important role in allowing our muscles to move. I'm specifically talking about its role in the sodium-potassium pump. Below is a diagram of how the pump functions.
There are a some important things to note. First, sodium is represented by "Na+" and potassium is represented by "K+". Second, for every 3 sodiums that exit the cell, 2 potassiums enter. Third, the "+" indicates the particles are electrically charged. So in the case of moving, being able to control the charge of the cells is important so as to not have our muscles stuck in a contraction (or a cramp), or unable to contract. Thus, sodium is a key player in our ability to move (the pump also has other functions, but I think understanding the need for motion is universal)!
Breaking particles is what fuels us (and we run on "rechargeable" batteries)
Let's marvel at how much energy is stored in bonds. My friend and I wanted to think of a way for my students to understand the amount of energy and we came up with the following demonstration. First, you show one liter of gasoline and ask students how much energy they think is stored in it. Second, you take your students to a school bus with no gas in its tank and pour the liter of gas in the tank. Third, you take the students for a ride until the bus comes to a stop and tell the students to push the bus back to school. Think of the students' faces! In case you are wondering, we calculated the bus would travel just under 3 miles on 1 liter of gasoline.
All that work of moving the school bus was contained in the bonds of the gasoline. More amazingly, the breaking of those bonds, or the burning of the fuel, is how the energy was released! The same thing is happening inside of us. Look up at the diagram above of the sodium-potassium pump. The star shape with "ATP" inside of it powers the pump, and you'll notice the "ATP" turns into "ADP". This represents one phosphate group left, or broke off, which is where the energy for the pump came from. Furthermore, that "ADP" will find another phosphate group and recharge to be used again. How incredible is that? All this renewable energy talk while our our cells have been doing it for a very long time!
Water is the coolest substance ever
What does all known life have in common? Water. It's unavoidable! But what exactly makes water so incredible? Below you will find a list of reasons why I think it's amazing.
- Accounts for 99% of the molecules of a living cell
- Universal solvent
- Solid state is less dense than its liquid state
- Great insulator
- Relatively high boiling point for its size
Think about number 1 for a moment. I remember going to parties and complaining about the girl-to-guy ratio if the party was 65% guys. In living cells, water molecules account for 99% of the party attendants! If something is found in that high of percentages, then it either is extremely common or is incredibly important. Considering dehydration leads to death, we can assume water must be incredibly important. The reasons 2-5 above explain its importance. But we should start by focusing on its primary function in living cells, which is the fact it is the universal solvent.
Kool-aid. Mountain Dew. Gatorade. These are examples of solutions with water being the solvent. The key idea here is that what goes into these drinks starts off in a visible state and then water seems to make it "disappear". We know this as dissolving. So all of the salts and sugars in your Gatorade are dissolved in the water primarily making it. Contrarily, alcohol and oils, which are also liquids, do not dissolve these same substances as well as water. How come? Look at the following pictures to help you understand.
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| Water gently flowing from the faucet |
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| Water bending toward combed plastic. |
These pictures indicate water has a charge. Well, overall a water molecule is neutral, but one side of it is positive while the other is negative. (And in case you were wondering, I charged the plastic pasta scoop by combing it through my hair). We label this phenomenon as polar. Because the water molecule is polar, it is attracted to many substances. Moreover, this attraction allows water molecules to dissolve, or break apart, other substances. Lucky for us, the cells in our body are able to use these smaller pieces of the other substances, such as the sodium and potassium ions mentioned above!
Boy I'm glad to be alive. Nothing beats it. I should thank my parents for everything they've done, but I should WORSHIP water! Life would not exist if water was a normal substance, meaning its solid state is more dense than its liquid state. Imagine if lakes froze from the bottom to the top. Goodbye fish. More importantly, life is thought to have started in pools of water. If ice didn't form an insulating barrier on top of the liquid water, then life would not have had the opportunity to evolve. Bow down to the water gods!
Ice also shows how water is a good insulator. The layer of ice that forms on top of a lake or any body of water allows the liquid water below it to stay liquid. Another example of water's amazing insulating property is how humidity affects the weather. If there is a high percentage of water vapor, then the temperature stabilizes. This has led to quite a few miserable summer nights due to humidity, but my little discomfort is worth it! Thank you water for helping my body maintain a stable temperature and keeping me alive!
Lastly for my praises of water is the fact it has a high boiling point. To understand just how amazing this is, one must first realize how incredibly small a water molecule is. The molecular weight of water is 18 amus (atomic mass units). If you compare this to other gases, say nitrogen and carbon dioxide, then you will get an idea of how small water is. The amus of nitrogen and carbon dioxide are 28 amus and 44 amus respectively. I mention this because states of matter depend partly on the speed of the particles. So let's look at bowling balls to help me clarify my point. Which would you be able to throw faster, an 8 pound or 12 pound bowling ball? An 8 pound ball would clearly be the correct answer. Notice that water molecules are smaller than the other two gases! What about water allows it to stay in liquid state when other larger molecules are gases?
The answer is simply the polarity of water. Water's polarity allows the water molecules to hold onto one another, which causes more energy to break them apart. Now, this is required in order for life to occur at a temperature range that other important substances, mainly carbon compounds, require for optimal effectiveness. Life requires a small, liquid substance capable of transporting things around. Water is like a small rowboat. It is capable of moving up narrow streams and in open oceans.
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