Students use a simple pH indicator to measure how much CO2 is produced during respiration, at rest and after exercising. They begin by comparing some common household solutions in order to determine the color change of the indicator. They review the concepts of pH and respiration and extend their knowledge to measuring the effectiveness of bioremediation in the environment.

In this interactive activity from the Building Big Web site, use your knowledge of bridge design to match the right bridge to the right location in a fictitious city.

Students act as engineers to learn about the strengths of various epoxy-amine mixtures and observe the unique characteristics of different mixtures of epoxies and hardeners. Student groups make and optimize thermosets by combining two chemicals in exacting ratios to fabricate the strongest and/or most flexible thermoset possible.

This activity is a lab project where students observe what happens when you try to mix oil and water. It can also be used to work with density.

In this Spreadsheets Across the Curriculum module, students build spreadsheets and draw graphs to explore a chemical buffer's ability to resist pH change, i.e., the buffer capacity. Quantification of buffer capacity is conceptually straightforward but involves multiple repetitive calculations. The key relationship is the Henderson-Hasselbalch equation: , which follows from the Law of Mass Action and The spreadsheets automate many of the calculations, thereby simplifying the process. Instead of focusing on the calculations, students can see what buffer capacity means and focus on the a deeper understanding of its implications. After reviewing several buffer calculations, the stduents use the spreadsheet to investigate buffer capacity graphically and characterize blood's physiological buffer system. While solving the question of how many breaths one can take before alkalosis sets in, the students manipulate a logarithmic equation, do "what if" modeling, and analyze rates of change from plots of their cacluated results.

We can combine our knowledge of acids and bases, equilibrium, and neutralization reactions to understand buffers and titrations. Solubility equilibria will build on concepts from solubility, precipitation, and equilibrium.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Student groups construct simple conductivity probes and then integrate them into two different circuits to test the probe behavior in solutions of varying conductivity (salt water, sugar water, distilled water, tap water). The activity culminates with student-designed experiments that utilize the constructed probes. The focus is to introduce students to the fabrication of the probe and expose them to two different ways to integrate the probe to obtain qualitative and quantitative measurements, while considering the application and utility of a conductivity probe within an engineering context. A provided handout guides teams through the process: background reading and questions; probe fabrication including soldering; probe testing and data gathering (including circuit creation on breadboard); probe connection to Arduino (including circuit creation and code entry) and a second round of testing and data gathering; design and conduct their own lab experiments that use the probes; online electrolyte/nonelectrolyte reading, short video, comprehension check and analysis questions.

Students learn about atoms and their structure (protons, electrons, neutrons) — the building blocks of matter. They see how scientific discoveries about atoms and molecules influence new technologies developed by engineers.

In this video segment adapted from ZOOM, the cast shows how the 34 steps in their Rube Goldberg invention use everything from gravity to carbon dioxide gas in order to accomplish one simple task: pouring a glass of milk.

In this video segment from ZOOM, Jillian explains how her simple machine uses marbles, levers, flowing sand, and a spinning wheel to water a plant.

This is a hands-on activity to assess the students understanding of peptide and disulfide bonds formed during protein synthesis. Students demonstrate the process of dehydration synthesis by combining amino acids through peptide bonds creating molecules of water, and one protein amino acid strand. It can also be used to assess students understanding of the process of translation.

How do you build a tunnel 32 miles long -- under water? This video segment adapted from Building Big, follows the construction of the Channel Tunnel (nicknamed "Chunnel"), the engineering wonder that connects England to France.

How can we slow the flow of energy on Earth to protect vulnerable coastal communities? Why is the sea level rising, causing some people to have to move? Initial student models in this unit propose a variety of ideas, but it seems like melting polar ice is a likely cause for this global phenomenon. Uncertainty and student concern for the people impacted motivate unit investigations that help students better understand the matter and energy flows that underlie a global phenomenon like polar ice melt and sea level rise.

OpenSciEd content is highly rated in EdReports and is aligned to NGSS standards.

What causes lightning and why are some places safer than others when it strikes? What causes lightning and why are some places safer than others when it strikes? This unit is designed to help students build a deeper understanding of atomic structure and atomic-scale force interactions through exploration of phenomena surrounding lightning and other static interactions. Students engage with stories and data about lightning and investigate a similar phenomenon in water droppers. They further investigate static interactions with various materials, including sticky tape, digging down to the subatomic level. Students apply these ideas back to lightning and further investigate force interactions, developing Coulomb’s law and ideas about polarization that can be applied to other phenomena. They identify electric fields as the source of the large energy transfers in lightning and explain lightning’s sudden behavior using ionization. They consider why structures made of certain materials provide protection from lightning and investigate why bodies of water, most of which contain dissolved salts, are particularly dangerous during storms. Finally, students develop a consensus model and transfer their understandings to the phenomena of airplane radomes and conducting gels used to simulate brains.

OpenSciEd content is highly rated in EdReports and is aligned to NGSS standards.

Why are oysters dying, and how can we use chemistry to protect them? Why are oysters dying, and how can we use chemistry to protect them? This unit is designed to build a deeper understanding about chemical reactions by exploring reversible reactions through exploration of ocean acidification. Students watch case videos, analyze data, and read about how movement of carbon dioxide from the atmosphere to the ocean makes the ocean more acidic. They consider how oyster die-offs may affect communities that rely on oysters for a food source. Students break down this large scale problem into a few key subproblems so they can use chemistry to try to solve them. They figure out how changes in concentration of H+ ions in water leads to changes in water pH. They use their knowledge of chemical reactions and mathematical thinking (stoichiometry) to determine the amounts of a substance they could use to neutralize acidic water. Students consider engineering trade-offs, criteria, and constraints to use chemistry to develop a design solution at a specific site to address oyster die-offs. They apply their thinking in a culminating task around increasing rates of ammonia fertilizer.

OpenSciEd content is highly rated in EdReports and is aligned to NGSS standards.

CK-12 Physical Science Concepts covers the study of physical science for middle school students. The 5 chapters provide an introduction to physical science, matter, states of matter, chemical interactions and bonds, chemical reactions, motion and forces, and the types and characteristics of energy.

In this activity you will be working with chemical reactions. In this activity, a cell phone has been dropped into a lake. Students will need to develop a device that that uses a chemical reaction to prevent a phone from sinking.

COSI Connects launches audiences of all ages into a universe of science through online videos, activities, plus a free mobile app that enables science exploration even when offline. COSI Connects is helping to bridge the digital divide, promote digital literacy, and address critical science education needs simultaneously. This repository of activities and videos is for learners of all ages and is a great supplement to at-home learning or for use in the classroom.

A lab where students determine the molarity of sugar and citric acid in samples of lemonade.