Chat Mats for Chemistry Teachers: Scaffolded Discussions that Stick
Using Chat Mats to Deepen Understanding in Chemistry and AP Chemistry
One of the most powerful ways to get students talking, reasoning and explaining their thinking in chemistry is by using chat mats. A chat mat is a tool that gives students a structured way to practice articulating their reasoning-whether they’re working in pairs, small groups, or as a whole class.
In both first-year chemistry and AP Chemistry, chat mats can be the key to helping students internalize how and why chemical concepts work.
What are Chat Mats?
A chat mat is basically a guided discussion organizer. Students are presented with a question, prompt, or problem on the mat, and then are provided with scaffolds-sentence starters, diagrams, or multiple-choice prompts-that help them frame a full scientific explanation.
Instead of giving students an open-ended question and hoping they know how to structure their response, chat mats offer a clear path. This allows students to practice Claim-Evidence-Reasoning (CER) style answers, connect vocabulary to visuals, and build confidence in constructing explanations.
Example: Periodic Trends in Atomic Radius
Take a look at the slide. The prompt asks “using atomic structure, explain why the atomic radius of Mg is larger than that of Al.”
On the left, students see Bohr models of magnesium and aluminum, along with their effective nuclear charges (Zeff). On the right, they are given sentence stems that guide them through their logic:
Mg has a smaller/larger effective nuclear charge.
The valence electrons are more/less attracted to the nucleus.
Therefore, the valence electrons will be closer to/further from the nucleus.
Which makes Mg’s atomic radius smaller/larger than aluminum’s.
By picking the correct response to complete the sentence, students not only come to the correct conclusion, but also practice using proper terminology like effective nuclear charge and attraction of valence electrons.
This structure encourages scientific reasoning.
Why Chat Mats Work
Scaffolded Thinking.
Students don’t freeze at an open-ended “why” question. Instead, they’re guided to build a reasoning claim.
Promotes Discussion.
When students work in pairs or small groups, they debate which choices make sense and justify their reasoning.
Formative assessment.
Teachers can quickly scan responses to spot misconceptions.
Bridges to free response questions.
In AP Chemistry, this style of scaffolded reasoning mirrors what students need to succeed on FRQs, where explanations must be supported by evidence and logic.
Classroom Implementation Ideas
Small groups. Have students collaborate to fill in a shared mat, then present their reasoning to the class.
Exit ticket. Print a mini version of the chat mat for students to complete individually at the end of class.
Differentiation. Provide more scaffolds for students who need extra support.
Partner talk. Project the chat mat on the screen and have partners talk through the mat before individually writing a free response or CER.
Beyond Periodic Trends
Chat mats can be adapted for nearly any chemistry topic. Here are some possibilities:
Bonding and polarity. Explain why a molecule is polar or nonpolar.
Thermochemistry. Justify whether a process is endothermic or exothermic.
Limiting reactants. Justify which reactant will be limiting.
Final Thoughts
Chat mats are a simple but powerful strategy to boost engagement, collaboration, and reasoning in chemistry. They give students the tools to construct strong scientific explanations, practice using vocabulary in context, and prepare for higher-level questions or assessments.
If you’d like to try them in your classroom, check out the example above and start experimenting with your own topics. Your students will be talking, reasoning, and thinking like chemists in no time!
Thanks for reading!
