When you teach molar mass, do you just throw up example problems? Or, is there a strategy behind the examples you choose?
There isn't a right way to teach students how to calculate molar mass, but there is definitely a wrong way! When you are choosing your examples, make sure that there is a reason behind that example.
Start with a simple example and then build ideas onto that example. Don't just jump in with a polyatomic ion containing compound and think that students will instantly understand molar mass if you just explain it really well. (Pssst....I did that!!!)
So, if you can't start with a polyatomic ion, what type of problem is good to start with?
The Problem: Students don't know the basic "chemistry language" when they start the class.
When you teach biology or anatomy or physics student already have a basic working knowledge of plants, and bones, and gravity. But chemistry is built on a table that they don't know and a lot of concepts they've never heard of that they need to master fairly quickly. This is why I color code as much as I can.
In the very beginning of my chemistry class I lay the foundation for color memory associations with cations and anions so that formula writing and bonding will be easier for my students. In my class, cations are always blue and anions are always yellow. I show them with this cation anion printable (#freebie). Sometimes I give them a blank one, and have them color it themselves, but a lot of the time I just hand this out and let them keep it for their references. Get the whole periodic table on my store, or join my email list here to access the whole periodic table packet (and more!) for free.
So, at this point they understand cations and anions, where they come from, where they are located on the periodic table, and that it is important to know the difference between the two.
Then, I send them home with a coloring activity. I like this because it is easy to grade and reinforces the color memory associate that will make learning the next chapter easier! This coloring activity is one page and has them color all the cations blue and all the anions yellow. Then, I have them write in all the charges on the cations and anions. This way the students are building on the idea that cations are positive, and have numerical charges. The same goes for anions.
A little later in the course we start to cover writing chemical formulas. I hand out a simple looking sheet with all these chemical formulas on it. All they have to do is color the cation blue and the anions yellow. I give them about 10 minutes to do that. After 10 minutes is up I ask them if they notice anything about the pattern within the chemical compounds. They usually are quick to say something like, "The first element is always blue, and the second element is always yellow."
Then I explain that when they write their compounds usually the cation will be first. If I happen to be teaching an honors, AP, or college intro class, I will gloss over the basics about electronegativity.
Next I teach them about balancing charges chemical formulas. I give them this worksheet that has a name of a chemical formula. Then, they go through draw a cation labeled with the element and charge. Then they draw an anion labeled with the element in charge. The next block asks them if they add up the charges, would it equal zero. They write yes or no AND show the math to prove it. The last block has them draw out the chemical compound. I find this really helps them SEE why we need to do this. Because like you, I GET TIRED OF ANSWERING WHY DO I NEED TO KNOW THIS. Moving on...
At this point you are probably wondering if we do anything besides color in my class and the answer is yes! Haha. I do a lot of other activities in class but I like to include quick coloring activities to draw attention, cement ideas a certain way, and make learning easier. So, once students have those foundations down, I have them do a higher level worksheet like this or this.
I hope this helped explain a few of my products. A lot of these links are paid links, but this link and this link were the freebies in the post. As always you can join my email list for more regular freebies.
The Problem: Many high school courses don't have time to go over formal charge, so you may need a refresher.
This is a complimentary post in order for you to understand more about the azide ion. To check out the ionic/covalent worksheet where this ion was introduced click here, or read the blog post of frequently asked questions here.
The problem: Sometimes an azide compound might look like a nitride compound at first glance!
I have a coloring worksheet that many middle school and high school teachers use to introduce or review ionic and covalent compounds. It's great because students color metals gray, nonmetals red, and polyatomic ions blue. This gives them a visual reinforcement that ionic and covalent compounds aren't just randomly established. There are rules. Using colors just makes it a little more fun! However, I get a few questions that come up on a regular basis that I'd like to clear up here.
I think the nitride ion has the wrong charge...
The Problem:Students hate taking notes because it requires more work on their part or they haven't been taught.
In our slide drenched classrooms where we post our PowerPoints and Prezis to our Google classrooms, students always have access to our notes. So, students think that they do not need to take notes since they have constant access to information. Some of my students have even said they have teachers that say not to take notes because they can get it online later. I haven't investigated, but I hope that isn't the case.
I was helping a student this week and I said, "Let me see your notes and I'll show you..." What I was saw was a bunch of scattered words on a piece of paper with no cohesion and thought process behind them. We harp about taking good notes, but let me ask you, have you ever taught a class how to take notes?
I haven't until now. Do you want to know what I learned?
Explain to your students that in order for your brain to store more information, you must process it as many times as you can.
Read it or listened to it-processed information once
Then, wrote it down as notes-processed information twice
Used notes to answer homework questions-processed information three times!
Notice there is no access it via Google Drive. :)
When we teach off a PowerPoint, they need to write down what is on the slide, along with your explanations. They can write it down during or after class, but they need to write it.
Here is the most important part for math and science classes especially. Teach the students to draw arrows from step to step.
Why did you divide in that step? What is produced in this step that is necessary for the next step?
What does this scientific cycle need this step? Where does that stuff come from?
Teach them to draw arrows.
Teach them to write down their questions.
Last, here is how I structure a 50 minute lesson around this idea.
Now, you can officially hold them accountable for their crappy notes!
The Problem: Students can't tell the difference in superscripts and subscripts when they learn to balance equations.
My solution is to teach this topic visually!
When I first started teaching, I'd look at the book that I was teaching out of and cut out several examples. My thought was that I would save time because once I had shown them the concept they should be fine, right?
Not so right.
Each of the examples in a book or lesson plan is usually teaching a different nuance of the topic. Once I realized that, I tried to accentuate that to my student by saying, "This example is an example of when you have this situation."
So, when I teach balancing chemical equations, I start by showing them a simple balanced equation. Then, we go though and count each atom type.
Then I show them an unbalanced equation.
We go through and count up each type of atom and they see that it is not balanced. Then I ask them how would we go about fixing this.
Usually a student suggests changing the subscript and at that point I draw this out to the side. I explain how the 2 subscript is explaining that the hydrogens come as a pair.
Next I ask what would happen if we had two of the NH3 Molecules instead of 1. First, I draw it. THEN I write it.
They usually see that the Nitrogens are now balanced and the hydrogens are not. I ask them how we could use math to turn 2 hydrogens into 6.
We usually get to an answer of 3 sets of 2 pairs of hydrogens. At this point I have them count on their papers and tell me if it is balanced.
The last thing I do is I write out the equation again with subscripts one color and superscripts another color. This leads us into the point that superscripts and subscripts are different and you can't just change superscripts into whatever you want.
Superscripts do not have Superpowers!
Hope that helps. If you'd like the free worksheet that goes along with this click here. There is a more involved($3) worksheet that is 3 pages and differentiated in levels here.
The Problem: All science teachers have a budget, and chemistry doesn't taste good.
Yup. I said it. We all have no money for labs. We often spend our own money for labs. But, what if we spent less and everyone got something out of it? So, even if you have to spend your own money you and the students get something tangible AND practical out of the lab. I'm talking about cooking with chemistry.
Crystallization, Saturation, Macromolecules and ...Fudge
Crystallization is a fascinating subject and if you let your students know how important this is to candy making, they just might pay attention. You can talk about how the boiling point depends on sugar concentration, and then lead that into a discussion on how seed crystals lead to crystal formation.
Boiling Point Elevation/Freezing Point Depression
Many teachers already use water for this lab and have students take measurements of the pure solvent and then with the solvent and salt, and again with sugar. But, what about taking this one step further by asking students to investigate whether adding salt to water is a significant way to raise the boiling point so that food cooks faster.(Hint: It isn't. You would need about a pound of salt for every quart of water to raise the boiling point by a degree or so. That's not going to end well. For anyone except Morton.)
I am currently working on a worksheet to demonstrate this concept, but it is still in the development stages. But, cake is a really cool way to explain macromolecules. Think about it! You have sugar(carbs), butter(lipid), eggs(protein), milk(protein or lipid), flour(carb), and based on each ingredient's purpose in the recipe you get cake.
When you look at each macromolecule you can also break it down into their monomer units. When you look at sugar you have glucose and fructose. Only after they get strung together do you get sucrose, and then those get strung together to become a carbohydrate.
You can do the same break down with the protein or the lipid.
I can break down just about any science subject into cooking so send me an email if you have a question or a lab that you would like a food-based idea for.
The Problem: Students can't see chemistry
I’ve been working with color memory techniques for seven years in the classroom and the question that I see come up over and over is, “What is color memory?" and "How do you use color effectively in your high school classroom?” I’m going to answer that question today.
When I got my first job out of college working as a lab tech I kept messing up the order of clear solvents that went into a process. I fixed my problem by color coding the labels on the solutions. Then, when I moved further into teaching and students would have a problem understanding a concept, I would use highlighters or color pencils to diagram concepts. I began to notice that I solved problems through color coding. I decided to further apply some of these techniques to my teaching, and it really helps students grasp concepts easier.
The Problem: Sometimes you get a class that will not behave.
If you are reading this, you have been there, or maybe you are right in the middle of it right now. If so, I'm sorry and I completely understand! At the beginning of my 3rd semester teaching, I was assigned this new curriculum that was going to change the world of math and solve all student problems with learning math. It was going to be a miracle.
It was a disaster.
But, it wasn't a total loss. I learned about the red folder trick.
There will be a lot of people who disagree with me-and that is okay. Different things work for different teachers. This is how I establish authority and style in my classroom. The number one way to catch and maintain authority in the classroom-is to prank the students on the first day of class.
Now, hear me out. I've tried it your way.
"Hi, I'm your teacher for Intermediate Algebra this semester. Please take a syllabus and pass the rest back. I expect you to read this in your own time. Lesson 1...."
Three minutes into it and they start asking if I really am the teacher.
"Are you old enough to teach this class?"
Nope. I'm not doing it that way again. I let 'em sit there.
It's 8:55 and the teacher isn't here yet.
It's 8:59 and the teacher isn't here yet.
Hi! I'm CoScine Creative. I have developed and run a tutoring center at a small college. I also teach some of their algebra and chemistry courses. And I will neither confirm nor deny pranking my students by pretending to be one.