Tips for Teaching Polyatomic Ions

I try to avoid having students memorize things, when possible.  I think it is far more valuable to be able to figure something out from other information or to be able to read and write science or to be able to think through a stoichiometry problem.  But when it comes to polyatomic ions, students just HAVE to memorize them.  There is no way around it.


It’s sort of like multiplication facts in elementary school.  When students are learning how to multiply, they can do a lot of different activities to teach them the logic behind multiplication.  They can practice with manipulative and iPad app games and such.  But in the end, each student HAS to memorize them because if they don’t, they will be unable to do multiplication problems in the future.


Polyatomic ions are the same way.  When you arrive at the nomenclature and bonding units of your year, they must memorize the polyatomic ions.  They will use their knowledge of the ions throughout the rest of the year in stoichiometry, acids and bases unit, equilibrium unit… They just need to memorize them.  Using them in problems from day to day will help too, but really, they just have to sit down and do the memorization work!


Here are a few ideas to help students memorize the polyatomic ions and their charges:


1.  Flash cards: I personally believe that for flash cards to be useful, students need to make them themselves.  The active part of creating them is just as important as practicing with them.  I have students put the name on the front and the formula on the back.  Or formula on the front and Lewis structure on the back if we are covering Lewis structures!



2.  Plain old Polyatomic ionic quiz that you tell them you’re giving!  Give them a list of them, give them a few days to memorize them, and tell them you are going to test 10 of them.  There is no partial credit.  Just flat out right or wrong.  I know it’s sort of old-fashioned, but this is what forced me back in the day to memorize them.  I recommend if you do this that you pick a different (or even random) 10 for each class period, because you know friends share which ions are asked in their class period.  Tell them it will be different for each class so they don’t even bother trying to cheat and talk between classes.



3.  Make it a competition!  You can do a quick-write on the board game where you ask your students.  Make a stack of small cards so you can pick a name randomly.  Have students form 2 or 3 teams (depending on how much chalkboard or whiteboard space you have) and have one student from each team go up at the same time.  Pick a card, shout out just the name (like “CARBONATE!”) and students have to write the formula down as fast as they can (or the Lewis structure if you’re in a more advanced section.)  Students love writing on the board and they love games.  You could throw the winning team an extra credit point on the next test, candy, or just bragging rights!


SPECIAL NOTE: My rule when I do this type of game in biology or chemistry class is absolutely no throwing my whiteboard markers.  Because if you do, you BUY me a new set.  I always spent quite a bit of my own money on nice colorful Expo whiteboard markers and it drove me nuts if students got cocky or angry during the game and threw the markers.

(Nick, you still owe me some markers, if you’re reading this…!  Yes, that was over 5 years ago.  But a rule is a rule!)



4. Play BINGO!  (Or “ATOMS”!)  You can find it here in my TeachersPayTeachers store.  I created a set of 30 unique bingo-style cards that students can use.  I include versions with formulas and versions with names, so you can have students practice finding the formula from the name or the name from the formula.  I even created custom markers for students to use on their sheets!  I love printing these on colored paper to make it even more fun.


What’s your favorite tip for teaching polyatomic ions?  Please add in a comment below!



science and math with mrs lau

Tips for Scaffolding in the Chemistry Classroom


Scaffolding, as many of you know, is a term educational experts (or people who want to sound fancy) use to describe how to break down a concept for students so that they can reach a goal or a level you want them to.  It’s like building a ladder (or scaffolding around a building being constructed) to help a student climb up or to build upon their knowledge and understanding until they reach what they need to reach.  There are a lot of different methods you can use to scaffold a concept in science and here are just a few techniques I use as I write my own lessons.


I think one of the most important things to do while planning scaffolding is to really think about the smaller, simpler skills or tasks students need to be able to do to accomplish something.



Let’s say I want my students to be able to complete this task:

“Predict what reaction will take place between a sodium atom and a chlorine atom and draw an electron dot diagram to show the reaction.”


When I think about scaffolding, I try to think about the many places or steps in the process that might trip up a student, and I try to create some sort of practice page or activity to help with those specific “tough spots” or “stumbling blocks” or “scaffold needs”.

Free Electron Dot Diagram Page

Download a free homework page for reviewing simple electron dot diagrams, and I'll also send you about one email a week with free resources and science teacher tips.

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In this example, to complete the electron dot diagram to show the reaction, the student would need to know how to do several smaller skills or think through several smaller steps.  Check out the flow chart below showing the smaller skills a student needs to draw a relatively simple electron dot diagram (Lewis structures) of a reaction to form sodium chloride.  Any one of these skills might trip up a student as they complete this relatively simple question.




Some students wouldn’t even need any scaffolding for this type of question.  But students who struggle with multi-step questions can really benefit from having a teacher go over each of these specific skills.  It really is a key skill of a good teacher, to be able to tell who and how many of his/her students need additional support at one of these tough spots or scaffolds.



So as a teacher, how do you anticipate what tough spots may occur when a student tries to complete a task?


Here are a few tips on coming up with and dealing with those tough spots.

1.  YOU do the task or problem and speak every thought that comes to mind out loud to hear yourself completing all of the steps that you normally do instinctually.  What you’ve done instinctually in chemistry or other science classes for years isn’t so instinctual to your students.


2. Write down every minor step or thought that you had to do or think to arrive at your goal for that task.  Is there any step that may seem difficult to a student or need reviewing before they are able to complete a particular task.


3. For each of these steps that might be “tough spots”, can you find a review worksheet or activity that you could use to help a student who needs help practice or review a skill?  The more you can anticipate and prepare ahead of time, the better your class will go!


4. I have found that when I am able to work with a student one-on-one (if the rest of the class is doing independent work or group work), often I can lead a student through questioning, helping them to arrive to the end of the task step by step, by asking them questions like the following list:


“What do you think you need to do next: do you have the right units you need?”


“If the end result needs this type of answer, and so far you have this… What do you need to do to get there?”


“What do you know about this particular chemical compound that might help you in this task?”


5.  Remember, in scaffolding, the goal isn’t to necessarily make the whole task EASIER for the student.  The goal is to give them the ladder they need to climb up to the achievement they seek!  Don’t give them the answer.  Don’t let them give up.  Give them just enough help (but not too much help!)



If you’d like an example of a few skill-type worksheets I use to help students review a particular skill, use the box below to subscribe and receive a free electron dot diagram page.  This page helps students practice their Lewis Structures for both atoms and ions!

Free Electron Dot Diagram Page

Download a free homework page for reviewing simple electron dot diagrams, and I'll also send you about one email a week with free resources and science teacher tips.

We won't send you spam. Unsubscribe at any time. Powered by ConvertKit

science and math with mrs lau

Back to School Secondary Science Giveaway


It’s time.


It’s copier hogging time.


It’s solution measuring time.


It’s microscope calibrating time, unpack-the-fetal-pigs time, and count-up-the-glassware time.


That’s right, it’s back to school for the science teacher.  And a bunch of us over at Teachers Pay Teachers want to make this back to school year special for you and save you a little time in the process.


Each of us has carefully designed materials that can save you a load of time in your classroom.  And this year for back to school, we are giving away FIVE $100 TPT Gift cards to five science teachers.


You can enter at the second Rafflecopter-box at the bottom of this blog post.  To enter, hop to all 18 blogs, write down the secret words each has hidden in their blog posts, and figure out the secret sentence (21 words in all).  Once you have the sentence, go to any one of the group giveaway Rafflecopter boxes, on any one of our blog pages, and type in the secret sentence in the right order.  We will pick five winners after it ends after midnight on Friday August the 11th.


My secret words: 1&2. “The Scientist”


Along with this giant group giveaway, I’m doing a separate giveaway of my own resources.  To check out my resources, check out my store here!  I’m giving away 5 $25 shopping sprees in my store.  All you have to do is enter in the Rafflecopter below and there are multiple ways to enter!



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Hope you have a terrific back to school season!


science and math with mrs lau

Scaffolding the Factor Label Method in the Chemistry Classroom


There is one particular part of chemistry class that trips up students a lot, and it’s using the factor label method.  Students need the factor label method for all sorts of conversion and stoichiometry problems throughout the entire year of chemistry.  The problem is that the factor label method itself is a combination of other skills, any of which a student might struggle with.


Here is a list of the skills students need to be able to do the factor label method and how I address them:


  1.  Reading the question! So many students, including ELL and non-ELL students, struggle with decoding a word problem and figuring out what the question is even asking.  And when chemistry vocabulary is involved, even more so.


How to address this reading need:


With struggling students, I create practice questions where all they do is tell me what key information is given in the problem and what they need to solve for in the problem solving process.  That way, I can identify and help students who need help reading the question and determining what the question is actually asking, because if they can’t read the problem, they certainly can’t do the problem.

Free Reading-The-Question Practice Page

Download a free homework page to help students who practice reading a word problem, and I'll also send you about one email a week with free resources and science teacher tips.

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2.   Practice path-finding!  Once students know what they are given and what the question is asking, students struggle with figuring out exactly how to get from “point A” to “point B”.  It takes a bit of practice to know that to calculate the length of time to build something in minutes when given years, that you have to convert years to days and then days to hours and then hours to minutes.  This “path-finding” problem compounds itself when students are learning a new concept in chemistry and they need to learn how to go from the mass of a reactant to the moles of that reactant to the moles of a product and then the mass (or volume or percent yield…) of the product.


How to address this pathfinding need:

With students who struggle with “path-finding”, I use practice questions that only ask them to figure out the path, not even do the calculations.  They practice looking up conversion factors and practice thinking through the chemistry, without worrying about pushing the right buttons on the calculator and getting it all wrong in the end.  By having students practice doing this, it also helps them practice WRITING DOWN ALL THEIR STEPS.  So often, students who struggle have a harder time than they would if they only wrote down their work.


3.  Practice the calculations!  Once they know what’s given and what they need to find and they have the path planned out, then the actual math or calculations can trip them up.  I have students who can write it all down but have a tough time pressing the right buttons on their calculator or <GASP> can’t do it by hand.  Arithmetic skills are at an all-time low (as you all know already) and when you’re a chemistry teacher, you’re a math teacher too!  I review the orders of operation in my chemistry class.


How to address this calculating need:

To help students to practice performing calculations, I do exercises in class where I set the whole problem up for them and then I have them set up the math and complete it.  Usually after a few practice rounds of this, I can identify students who are struggling with the math and get them extra support.


And here’s another quick tip for teaching the factor label method:

When I was taught the factor label method back in as a high school sophomore in Mrs. Sears’ honors chemistry, I was taught to write the conversion factors in “monkey bars”, which is what she called them!  Instead of parenthesis/fractions, she had us write them like this:


You know, I still use them in my own problem solving and in my classroom.  There is just something a little simpler about writing a grid instead of writing ( ) ( ) ( ) ( ).  Fewer lines to mess up and I think it really helps students (like me!) with pretty terrible handwriting.


If you would like to check out my factor label method pages, you can find them here.

They are included in my Differentiated Chemistry Homework for the Whole Year Bundle here.

science and math with mrs lau

It’s been a while

I haven’t posted on my blog in a while, but I’ve been busy!  With a 1 year old and a 5 year old running around, this is what I’ve been spending my precious few works hours on:


After finishing my huge biology homework bundle (you can see it here!) I started creating a chemistry one.  And as I’m beginning it, I know it’s going to be not only huge, it’s going to be HUGE.  I have a few big plans for it.

  1. Scaffolding: Chemistry is a skills-based subject.  It requires a bunch of specific math and lab skills (factor label method, scientific notation, measurement, metric conversions, etc).  I really want to have specific pages that help teachers really hone in on the specific part of problem solving that a particular student is struggling with.
  2. Workspace: Every page will have room for students to complete their work on the same page as the problem.  You know how when students copy questions out of a textbook, they often copy it wrong?  Or they don’t copy the question and just write their work and the answer, forcing them to have both their notebook and textbook together at all times (or worse, a random loose leaf piece of paper)?  I want all the work and questions on the same page.  I also see students with specific learning needs who struggle with going from one page to the next and being able to work from both at the asme time.
  3. Problem-solving Guidance: To encourage students to WRITE DOWN ALL THE STEPS, I’m building into the practice pages a set of icons.  These icons will be used throughout the pages to tell students to do the following: write what’s given, write what units the answer will be in, write down the conversion factors needed, write down the chemical equation, etc etc.  This will guide students to write down what they need to write down.

If you want to read more about my chemistry homework bundle, you can go here!  I’ll be creating a unit a month for the next 12 months.  If you’d like to get notified when I add new units to the bundle, you can sign up for my email list here!


What would you like to see in my chemistry bundle?  Comment below and let me know!