Task Title: Alkali Metals: Patterns in Reactivity
Grade: High School
Date: [Current Date]
What was in the task, where was it, and why is this evidence?
Yes. The phenomenon is the varying violence and speed of reactions when different alkali metals (Li, Na, K) are dropped into water.
Yes. Students must interact with the simulation to gather macroscopic data (reaction time, peak temperature, visual effects like sparks/flames) and microscopic data (atomic models, number of shells, valence electrons) to answer the analysis questions.
Features of engaging, relevant, and accessible tasks:
| Features of scenarios | Yes | Somewhat | No | Rationale |
|---|---|---|---|---|
| Scenario presents real-world observations | [x] | [ ] | [ ] | Students observe simulated real-world chemical reactions with accurate physical behaviors (sinking, floating, bubbling, igniting). |
| Scenarios are based around at least one specific instance, not a topic or generally observed occurrence | [x] | [ ] | [ ] | The scenario is based around specific instances of dropping individual elements into water and observing the specific outcome. |
| Scenarios are presented as puzzling/intriguing | [x] | [ ] | [ ] | The increasing violence of the reactions, and the inclusion of a highly explosive “Mystery Metal”, is intriguing. |
| Scenarios create a “need to know” | [x] | [ ] | [ ] | Students need to know why the reactions are different to predict the identity of the mystery metal. |
| Scenarios are explainable using grade-appropriate SEPs, CCCs, DCIs | [x] | [ ] | [ ] | The phenomenon is explainable using HS-level models of atomic structure and periodic table patterns. |
| Scenarios effectively use at least 2 modalities (e.g., images, diagrams, video, simulations, textual descriptions) | [x] | [ ] | [ ] | Uses interactive simulation, data readouts, and atomic diagrams. |
| If data are used, scenarios present real/well-crafted data | [x] | [ ] | [ ] | The simulation provides sensor readouts for peak temperature and reaction duration. |
| The local, global, or universal relevance of the scenario is made clear to students | [ ] | [x] | [ ] | While chemical reactivity is universally relevant, it is not explicitly tied to a local community issue in this specific task. |
| Scenarios are comprehensible to a wide range of students at grade-level | [x] | [ ] | [ ] | The simulation provides clear visual and textual feedback. |
| Scenarios use as many words as needed, no more | [x] | [ ] | [ ] | Instructions are concise and direct. |
| Scenarios are sufficiently rich to drive the task | [x] | [ ] | [ ] | The data provided by the simulation is exactly what is needed to build the explanatory models. |
| Evidence of quality for Criterion A: [ ] No | [ ] Inadequate | [x] Adequate | [ ] Extensive |
Suggestions for improvement of the task for Criterion A:
None at this time. The simulation provides a strong, observable phenomenon.
Consider in what ways the task requires students to use reasoning to engage in sense-making and/or problem solving.
Students must reason about how the number of electron shells (distance from the nucleus) affects the reactivity of the single valence electron in Group 1 metals, and then use that reasoning to predict the properties of an unknown element.
Evidence of SEPs (which element[s], and how does the task require students to demonstrate this element in use?)
Developing and Using Models: Students use the interactive atomic models provided in the simulation to identify patterns in electron configuration (shells and valence electrons) and relate them to macroscopic phenomena.
Evidence of CCCs (which element[s], and how does the task require students to demonstrate this element in use?)
Patterns: Students explicitly look for patterns in macroscopic reactivity (increasing violence) and microscopic structure (increasing number of shells, constant valence electrons) as they move down Group 1.
Evidence of DCIs (which element[s], and how does the task require students to demonstrate this element in use?)
PS1.A: Structure and Properties of Matter: Students apply their understanding that the periodic table organizes elements by their outermost electron states, which dictate their chemical properties and reactivity.
Consider in what ways the task requires students to use multiple dimensions together.
Students use models (SEP) of atomic structure (DCI) to identify patterns (CCC) that explain the varying violence of the alkali metal reactions (phenomenon).
Consider in what ways the task explicitly prompts students to make their thinking visible (surfaces current understanding, abilities, gaps, problematic ideas).
The analysis questions require students to explicitly state the patterns they observe, identify the shared and changing structural features, and provide reasoning for their prediction of the Mystery Metal.
| Evidence of quality for Criterion B: [ ] No | [ ] Inadequate | [x] Adequate | [ ] Extensive |
Suggestions for improvement of the task for Criterion B:
None. The three dimensions are tightly integrated.
Consider specific features of the task that enable students to make local, global, or universal connections to the phenomenon/problem and task at hand. Note: This criterion emphasizes ways for students to find meaning in the task; this does not mean “interest.” Consider whether the task is a meaningful, valuable endeavor that has real-world relevance–that some stakeholder group locally, globally, or universally would be invested in.
Understanding reactivity patterns is universally relevant to chemistry and material science, helping explain why certain materials are safe or dangerous.
Describe what modes (written, oral, video, simulation, direct observation, peer discussion, etc.) are expected/possible.
Students respond via written explanations based on direct observation and interaction with a simulation.
| Features | Yes | Somewhat | No | Rationale |
|---|---|---|---|---|
| Task includes appropriate scaffolds | [x] | [ ] | [ ] | The task builds sequentially from observing knowns to predicting unknowns. |
| Tasks are coherent from a student perspective | [x] | [ ] | [ ] | The progression makes logical sense. |
| Tasks respect and advantage students’ cultural and linguistic backgrounds | [x] | [ ] | [ ] | Relies heavily on visual data rather than dense text. |
| Tasks provide both low- and high-achieving students with an opportunity to show what they know | [x] | [ ] | [ ] | Basic pattern recognition is accessible, while the final prediction requires higher-level synthesis. |
| Tasks use accessible language | [x] | [ ] | [ ] | Uses standard, grade-appropriate scientific terminology. |
Consider how the task cultivates students interest in and confidence with science and engineering, including opportunities for students to reflect their own ideas as a meaningful part of the task; make decisions about how to approach a task; engage in peer/self-reflection; and engage with tasks that matter to students.
The interactive nature of the simulation, particularly the explosive “Mystery Metal”, cultivates interest.
Consider the ways in which provided information about students’ prior learning (e.g., instructional materials, storylines, assumed instructional experiences) enables or prevents students’ engagement with the task and educator interpretation of student responses.
The background section provides the necessary context regarding groups, periods, and valence electrons to ensure students can engage with the simulation.
Describe evidence of scientific inaccuracies explicitly or implicitly promoted by the task.
No inaccuracies found. The relative reactivity, flame colors (e.g., lilac for potassium), and atomic models reflect accepted scientific principles.
| Evidence of quality for Criterion C: [ ] No | [ ] Inadequate | [x] Adequate | [ ] Extensive |
Suggestions for improvement of the task for Criterion C:
None.
Before you begin:
The task assesses HS-PS1-1: Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.
Consider the following:
Yes, students must use the pattern of outermost electrons to answer the final question.
No.
Yes, the final prediction question clearly demonstrates whether they can apply the pattern.
Consider what student artifacts are produced and how these provide students the opportunity to make visible their 1) sense-making processes, 2) thinking across all three dimensions, and 3) ability to use multiple dimensions together [note: these artifacts should connect back to the evidence described for Criterion B].
The written answers to the analysis questions serve as direct, observable evidence of their reasoning.
Consider how well the materials support teachers and students in making sense of student responses and planning for follow up (grading, instructional moves), consistent with the purpose of and targets for the assessment. Consider in what ways rubrics include:
Teachers can evaluate if students correctly identify the pattern (CCC), map it to the atomic model (SEP), and state the relationship to reactivity (DCI).
The questions are broken down into smaller steps to isolate where a student might struggle (e.g., identifying the pattern vs applying the pattern).
This task naturally leads into discussions of electronegativity and ionization energy.
Consider any confusing prompts or directions, and evidence for too much or too little scaffolding/supports for students (relative to the target of the assessment—e.g., a task is intended to elicit student understanding of a DCI, but their response is so heavily scripted that it prevents students from actually showing their ability to apply the DCI).
The directions are straightforward and guide the student through the simulation without giving away the answers.
| Evidence of quality for Criterion D: [ ] No | [ ] Inadequate | [x] Adequate | [ ] Extensive |
Suggestions for improvement of the task for Criterion D:
None.
Consider the task purpose and the evidence you gathered for each criterion. Carefully consider the purpose and intended use of the task, your evidence, reasoning, and ratings to make a summary recommendation about using this task. While general guidance is provided below, it is important to remember that the intended use of the task plays a big role in determining whether the task is worth students’ and teachers’ time.
The task effectively leverages an interactive simulation to engage students in three-dimensional sense-making. It aligns tightly with HS-PS1-1 by requiring students to identify patterns in atomic structure to explain reactivity phenomena. All criteria are met adequately.
Final recommendation (choose one):