Perceiving is more than just looking at an object or thinking about an idea – it is extensively examining it – noticing subtle differences and deciphering patterns with as many senses as possible.
The idea of the mole in chemistry is often a hard concept to perceive by the novice chemist – a simple glance tells you its just a big number 6.022 x 10^23 or represented in normal notation as 602,200,000,000,000,000,000,000. For a new student to chemistry however, I want them to feel how big that is and get a sense of its magnitude.
As a type of re-imagination, I wanted to perceive one mole in a different way. I wanted to get a visual of how big one mole of 1's would be. Starting from the bottom up, I wanted to build an image so the students could almost see one mole. What does 10 1's look like? 100? 1,000? 10,000? Let's keep building it until we get to 10^23 (about a trillion trillion) How many sheets of paper would it fill? How many books of sheets? How much volume could those books fill? The end result is the realization that one mole of 1's would fill enough sheets of paper to fill up Lake Michigan 91 times! Being at a school close to the shore of Lake Michigan, my students have all seen the lake and how broad and wide it is. You cannot even see the other side where Wisconsin is. Yet, it is more than just breadth in area, it is depth as well (which the students can only imagine how deep Lake Michigan is). With this new re-imagination, I hope my students will feel the weight of what 1 mole is. We also take a look at some other comparisons like one mole of watermelon seeds, one mole of pennies and one mole of grains of sand.
This new understanding can really help my students with the topic of the mole. Not only can they get a glimpse at the enormity of Avogadro's number (one mole), but they can also get a different sense at how small atoms and molecules are. To say that a bag full of sugar in your hands can be more molecules than all the stars in the sky is mind blowing. A trillion trillion atoms can fit on your hand – that means they must be so very, very small – a seemingly incomprehensible size – just as one mole is a seemingly incomprehensible huge number.
A pattern is a repeating sequence of a common variable often in an expected manner, but sometimes unexpected. In dealing with the mole in chemistry, we often have many calculations – calculating the molar mass of a substance, converting between mass and moles, and calculating the heat of enthalpy of a reaction – just to name a few. For this exercise of patterning, I will use the calculation of molar mass as my example.
Calculating the molar mass of a substance follows a particular pattern or method. Once they students learn the pattern of calculation, most of my students report enjoying this type of chemistry calculation. As indicated by the diagram below, you can calculate the molar mass of any substance as long as you know the composition of elements. The pattern is the following: multiply the number behind the element symbol (the subscript) by the atomic mass from the periodic table. Do that for each element given for the compound then add up all of the masses together. Written out...
Atomic mass x number + atomic mass x number + atomic mass x number …. etc... The pattern that some students have difficulty learning is when to multiply and when to add. Sometimes they do the opposite order or they may simply multiply all the numbers together.
In brainstorming for new patterns with this calculation, I noticed that we always use the addition symbol (+) between different elements. I've never specifically told the students that connecting pattern. When drawing out the calculation, it looked like a cross or a bridge – perhaps a bridge from one element to another! This could be an important memory cue for students to remember to use addition when going between elements. Switching to a different element, they need to make a bridge first! That's a pattern they can remember every time they do a molar mass calculation.
Abstraction is stripping away the peripherals of a particular reality to get at the essence of its being.
For abstraction of the mole, I chose three representations: two visual and one textual representation of the mole(although the textual representation has visual aspects to it as well). One of the key concepts of the mole is that it is both an incredibly large number and while at the same time, the atom is an incredibly small piece of matter. For figure 1, I started with a very small dot that is hard to see (like an atom) and copied it over and over again until I got a very large number that would be incredibly difficult to count. While it isn't exactly the number that a mole represents, it gets at the essence of what a mole is – a large, uncountable number – and in chemistry we count an incredibly small object – the atom. For figure 2, I contrasted a large circle with a small circle – highlighting the essence of enormity of the number (too big to fit on the paper) and the minuscule nature of what the number is counting (too small to read). For figure 3, I contrast again the large and small principle, but using words that get incredibly small and incredibly large – it forces one to extrapolate what the rest of the sentence would say. Like many abstractions, not all of the picture is obvious at the beginning, but can be inferred and interpreted.
These abstractions hopefully can help students capture the essence of what I'm trying to teach them about the mole and the implications for chemistry. The enormity and the tininess of the mole is an important dichotomy that can't be emphasized enough and hopefully abstracting it down can help students grasp the concept.
Embodied Thinking is using one's body to enter into a concept through position, movement or simply imagining what it would feel like to be something other than what you are. Empathy is a related concept where you imagine what it would be like to be another being.
To kinesthetically think about the mole, I chose two positions to contemplate the meaning of a mole. The first position is that of looking up at the sky – looking for the stars in the sky – almost trying to count them. To be a simple atom counted among a mole – it is like looking up at the sky at the billions of stars in the sky – feeling so small and insignificant.
The second position is that of looking down at your hands – imagining all the atoms contained in your body – countless upon countless numbers of atoms. Such a contrast – even as you feel so small looking at the sky, you realize what we are made of and the complexities in our body and it is amazing to think about and the significance we are given.
I am hoping that this imagination exercise and use of our bodies will help students to stretch their imaginations. What would it feel like to be like an atom? What does it feel like to be a small atom in a uncountable mole of atoms? Look up at the stars and imagine what it feels like. However the students do not have to look far to find these countless masses of atoms – simply look back down at your hands and see them. Simply in your hands alone there are trillions upon trillions of atoms. Imagine how small you felt when looking up at the sky and now imagine being that small inside your hands as a small little atom.
In a sense, we are trying to empathize with an atom – similar to how Albert Einstein when he imagined being a photon of light moving along super fast and picturing the sensations he would have felt as that photon. I'm hoping this thought experiment of grand (and yet small) proportions will help my students to move beyond the abstractions and make the mole feel more concrete.
Modeling is attempting to depict visually what is difficult to access otherwise. In regards of the concept of the mole in chemistry class, it is difficult to imagine the magnitude of how massive a mole is. It is essential for a chemistry teacher to come up with some comparisons, images and models of the mole to help capture for the students some way of understanding the mole's magnitude.
Using a number of everyday objects, we can create a model of what one mole of that object would look like. One mole of watermelon seeds would be found in a watermelon approximately the size of the moon. 1 mole of donut holes would cover the whole earth not just once, but it would also be 5 miles deep. 1 mole of pennies would make stacks that reach up to the sky – reaching the moon seven times.
For my models, I altered pictures to create an image consistent with these imaginary situations. Through these images, it will hopefully capture the minds of my students to help picture what is otherwise impossible to see with their own eyes. Zooming out is essential due to the sheer magnitude of the number associated with the mole. Atoms are so very small – that it makes it hard to realize the incredible size of the mole without using some the size of everyday objects and zooming out so you can “see” the number. That is why massive objects like the earth and moon are helpful to compare the size of the mole to when using everyday objects.
Play can be an important component in fostering creativity and interest in a unit. Students may feel overwhelmed with learning something new and feel like they have to get it perfect. Play helps create an atmosphere of fun and low-risk dabbling in the topic.
In the unit of the Mole, we do many conversions and calculations of molar mass. It is very helpful for students to know their periodic table well and where the elements are located. This is why this activity is both playful/fun and meaningful in our unit.
Creativity is essential in teaching the Mole Unit in Chemistry class. I want my students to perceive more than just what is visible at face value about the idea of the mole – extensively examining and noticing subtle differences and deciphering patterns with as many senses as possible. I want students to look for patterns – looking for a repeating sequences of a common variables. I want my students to use abstraction – to stripe away the peripherals of a particular reality to get at the essence of its being. I want my students to embody the concept of the mole - using one's body to enter into the concept through position, movement or simply imagining what it would feel like to be something other than what you are. I want my students to be able to model the mole - attempting to depict visually what is difficult to access otherwise. Lastly, I want students to be able to play with the concept of the mole and to engage with the concept in a low-risk activity. All of these components of creativity I believe will greatly bolster our Chemistry curriculum.
Foster interest and deep thinking about The Mole in Chemistry class using these essential components of creativity. Click Here for more.