Chemical Energy
Which of the following is an example of using a chemical process to release energy? (choices: cutting wood into small wood chips; dissolving copper chloride powder in a beaker of water; using a battery to power a flashlight; heating an ice cube to melt it)
Using a battery to power a flashlight
Mary makes a first version of her headphone-tangle product from materials at home. This first version is known as: (choices: an experiment; a prototype; a constraint; a criterion)
A prototype
What is step 1 of the engineering design process?
Identify / define the problem
Do reclaimed metals disappear during chemical recovery? Explain.
No — the metal has not disappeared; it remains present but in a different form or location
When an endothermic chemical reaction absorbs thermal energy from the environment, which describes the temperature change of the products vs the reactants?
The temperature of the products is lower than the temperature of the reactants
You use Mary's product for five days, track how well it works, give feedback, and Mary makes another version. Which part of the design process did you help with? (choices: identifying the problem; designing the product; building the product; testing and evaluating the product)
Testing and evaluating the product
What is step 2 of the engineering design process?
Brainstorm the Solution
Why build and test multiple prototypes before final product?
To find and fix flaws, improve usability and performance, reduce risk and long‑term cost, and produce a more reliable final product
Which process releases energy by breaking chemical bonds in fuel and forming new bonds in combustion products?
Combustion (chemical reaction)
The criteria for a design project describe: (choices: the end use of the design; the limitations of the design; the purpose of the design; the requirements of the design)
The requirements of the design
What is step 3 of the engineering design process?
Design
Design a cold pack that uses a chemical reaction to absorb heat. Describe at least two design criteria and explain why you chose each.
Example criteria: must reach/maintain 0–10^C} for ≥20 minutes (effective treatment); safe for skin contact (user safety).
Which is an example of storing chemical potential energy for later use? (choices: lifting a book on a shelf; charging a rechargeable battery; rubbing hands together; melting wax)
Charging a rechargeable battery
The constraints for a design project describe: (choices: the end use of the design; the limitations on the design;the purpose of the design; the requirements of the design)
The limitations on the design
What is step 4 of the engineering design process?
Build
For the same cold pack, describe at least two constraints and explain why you chose each.
Example constraints: use non‑toxic, readily available materials (safety + cost); activation and production must be low‑cost and manufacturable (feasibility).
A reaction that releases energy to its surroundings is called ______; one that absorbs energy is called ______. Fill in the blanks.
Exothermic; endothermic
Which term describes a quick, low‑cost model built to test a single idea or function before building a more complete prototype?
A proof of concept (or mock‑up)
What is step 5 -7 of the engineering design process?
5. Test 6. Improve/Redesign 7. Share Solution!
Suggest one test you would run to evaluate the cold pack's performance and one metric you would record.
Test: measure temperature over time when activated and applied to a simulated injury; Metric: minimum temperature reached and duration