Build Thermal Energy Device - Middle School Physical Science
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What is the name of the energy stored in chemical bonds that can change during a reaction?
What is the name of the energy stored in chemical bonds that can change during a reaction?
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Chemical potential energy. Energy stored in bonds that changes during reactions.
Chemical potential energy. Energy stored in bonds that changes during reactions.
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What is the formula for thermal energy change of a sample when no phase change occurs?
What is the formula for thermal energy change of a sample when no phase change occurs?
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$q = mc\Delta T$. Heat equals mass times specific heat times temperature change.
$q = mc\Delta T$. Heat equals mass times specific heat times temperature change.
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What does $c$ represent in the equation $q = mc\Delta T$?
What does $c$ represent in the equation $q = mc\Delta T$?
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Specific heat capacity. Amount of heat needed to raise 1g by 1°C.
Specific heat capacity. Amount of heat needed to raise 1g by 1°C.
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Identify the correct units for $q$ in $q = mc\Delta T$ used in middle school science.
Identify the correct units for $q$ in $q = mc\Delta T$ used in middle school science.
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Joules (J). SI unit for energy and heat.
Joules (J). SI unit for energy and heat.
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What is the term for an insulated container used to reduce heat transfer during measurements?
What is the term for an insulated container used to reduce heat transfer during measurements?
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Calorimeter. Insulated container minimizes heat exchange with surroundings.
Calorimeter. Insulated container minimizes heat exchange with surroundings.
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What is the term for a chemical process that releases thermal energy to the surroundings?
What is the term for a chemical process that releases thermal energy to the surroundings?
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Exothermic reaction. Releases heat to surroundings, making them warmer.
Exothermic reaction. Releases heat to surroundings, making them warmer.
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What is the term for a chemical process that absorbs thermal energy from the surroundings?
What is the term for a chemical process that absorbs thermal energy from the surroundings?
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Endothermic reaction. Absorbs heat from surroundings, making them cooler.
Endothermic reaction. Absorbs heat from surroundings, making them cooler.
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What is the term for the total thermal energy of particles due to motion and position in matter?
What is the term for the total thermal energy of particles due to motion and position in matter?
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Thermal energy. Total kinetic and potential energy of all particles.
Thermal energy. Total kinetic and potential energy of all particles.
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What is the term for the average kinetic energy of particles, measured in $^\circ\text{C}$ or K?
What is the term for the average kinetic energy of particles, measured in $^\circ\text{C}$ or K?
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Temperature. Measures how fast particles are moving on average.
Temperature. Measures how fast particles are moving on average.
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What is the safest container material choice for a student chemical hot/cold pack: glass or flexible plastic?
What is the safest container material choice for a student chemical hot/cold pack: glass or flexible plastic?
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Flexible plastic. Plastic won't break if dropped, preventing spills.
Flexible plastic. Plastic won't break if dropped, preventing spills.
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Identify the purpose of using two compartments separated by a breakable seal in a thermal pack.
Identify the purpose of using two compartments separated by a breakable seal in a thermal pack.
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To keep reactants separate until activation. Prevents reaction until user breaks seal to mix.
To keep reactants separate until activation. Prevents reaction until user breaks seal to mix.
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Which observation indicates an exothermic reaction in a pack: temperature increases or decreases?
Which observation indicates an exothermic reaction in a pack: temperature increases or decreases?
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Temperature increases. Heat released raises temperature of the pack.
Temperature increases. Heat released raises temperature of the pack.
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Which design feature best increases heat transfer to a hand: insulating outer layer or thin flexible outer layer?
Which design feature best increases heat transfer to a hand: insulating outer layer or thin flexible outer layer?
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Thin flexible outer layer. Thin material allows heat to flow easily to hand.
Thin flexible outer layer. Thin material allows heat to flow easily to hand.
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Find $q$ if $m = 100,\text{g}$, $c = 4.18,\text{J/(g}\cdot^\circ\text{C)}$, and $\Delta T = 5,^\circ\text{C}$.
Find $q$ if $m = 100,\text{g}$, $c = 4.18,\text{J/(g}\cdot^\circ\text{C)}$, and $\Delta T = 5,^\circ\text{C}$.
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$q = 2090,\text{J}$. $q = (100)(4.18)(5) = 2090,\text{J}$
$q = 2090,\text{J}$. $q = (100)(4.18)(5) = 2090,\text{J}$
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Identify the correct conclusion if the water gains $q = 500,\text{J}$ from a reaction in a calorimeter.
Identify the correct conclusion if the water gains $q = 500,\text{J}$ from a reaction in a calorimeter.
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The reaction released $500,\text{J}$ (exothermic). Water gained heat that reaction lost (exothermic).
The reaction released $500,\text{J}$ (exothermic). Water gained heat that reaction lost (exothermic).
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Which design choice best reduces heat loss from a hot pack: thin metal shell or thick foam insulation?
Which design choice best reduces heat loss from a hot pack: thin metal shell or thick foam insulation?
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Thick foam insulation. Insulation prevents heat from escaping to surroundings.
Thick foam insulation. Insulation prevents heat from escaping to surroundings.
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Which heat transfer method requires direct contact between materials in a thermal energy device?
Which heat transfer method requires direct contact between materials in a thermal energy device?
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Conduction. Heat flows through direct particle collisions.
Conduction. Heat flows through direct particle collisions.
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Which observation indicates an endothermic process in a pack: temperature increases or decreases?
Which observation indicates an endothermic process in a pack: temperature increases or decreases?
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Temperature decreases. Heat absorbed lowers temperature of the pack.
Temperature decreases. Heat absorbed lowers temperature of the pack.
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Identify the correct activation step for a two-chamber cold pack with water and solid: mix the contents or keep them separated?
Identify the correct activation step for a two-chamber cold pack with water and solid: mix the contents or keep them separated?
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Mix the contents. Allows the reaction to begin.
Mix the contents. Allows the reaction to begin.
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What is the key safety reason to avoid using open flames for a chemical thermal energy device?
What is the key safety reason to avoid using open flames for a chemical thermal energy device?
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Fire and burn hazard from uncontrolled heat release. Open flames create dangerous, uncontrolled reactions.
Fire and burn hazard from uncontrolled heat release. Open flames create dangerous, uncontrolled reactions.
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Which option is commonly exothermic in hot packs: crystallizing sodium acetate or dissolving ammonium nitrate?
Which option is commonly exothermic in hot packs: crystallizing sodium acetate or dissolving ammonium nitrate?
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Crystallizing sodium acetate. Releases heat as it forms solid crystals.
Crystallizing sodium acetate. Releases heat as it forms solid crystals.
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Which option is an endothermic process used in instant cold packs: dissolving $\text{NH}_4\text{NO}_3$ or burning fuel?
Which option is an endothermic process used in instant cold packs: dissolving $\text{NH}_4\text{NO}_3$ or burning fuel?
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Dissolving $\text{NH}_4\text{NO}_3$. Ammonium nitrate absorbs heat when it dissolves.
Dissolving $\text{NH}_4\text{NO}_3$. Ammonium nitrate absorbs heat when it dissolves.
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Which design feature most directly prevents chemicals from contacting skin in a thermal pack?
Which design feature most directly prevents chemicals from contacting skin in a thermal pack?
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A sealed, leak-resistant outer bag. Contains chemicals safely inside the device.
A sealed, leak-resistant outer bag. Contains chemicals safely inside the device.
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What is the direct purpose of a barrier or inner pouch in many thermal energy pack designs?
What is the direct purpose of a barrier or inner pouch in many thermal energy pack designs?
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Keeps reactants separated until activation. Prevents premature reaction before use.
Keeps reactants separated until activation. Prevents premature reaction before use.
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What are the surroundings in a chemical hot pack or cold pack device?
What are the surroundings in a chemical hot pack or cold pack device?
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The pack material, air, and the user’s hand/body. Everything outside the system that can exchange heat.
The pack material, air, and the user’s hand/body. Everything outside the system that can exchange heat.
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