front 1 -Chemical Reaction: | back 1 A process where atoms rearrange to form new substances (e.g., burning wood turns it into ash and gases). |
front 2 - Reactant: | back 2 A substance that starts a chemical reaction (e.g., wood and oxygen in a fire). |
front 3 - Product: | back 3 A substance formed after a chemical reaction (e.g., ash and carbon dioxide from burning wood). |
front 4 -Conservation of Matter: | back 4 The total mass of reactants equals the total mass of products; atoms are neither created nor destroyed. |
front 5 - Exothermic Reaction: | back 5 A reaction that releases heat or light (e.g., burning a match). |
front 6 - Endothermic Reaction: | back 6 A reaction that absorbs heat (e.g., photosynthesis). |
front 7 - Activation Energy: | back 7 The energy needed to start a chemical reaction. |
front 8 - Cellular Respiration: | back 8 A metabolic reaction in the body that breaks down food (glucose) with oxygen to release energy, producing carbon dioxide and water. |
front 9 - Metabolic Reactions**: | back 9 Chemical reactions in living organisms that provide energy (e.g., digesting food). |
front 10 1. What is a chemical reaction? | back 10 A process that rearranges atoms to form new substances - Explanation: A chemical reaction changes the way atoms are bonded, creating new substances (e.g., rust forming on iron). |
front 11 2. What is the anchoring phenomenon in the Chemical Reactions and Matter unit?** | back 11 How a match burns and produces light - Explanation: The burning match is used to show how reactants (wood, oxygen) turn into products (ash, gases) and release energy. |
front 12 3. What is formed that indicates a chemical reaction has occurred? | back 12 a gas or precipitate - Explanation: Signs of a chemical reaction include gas bubbles, a solid (precipitate) forming, or color changes, not just physical changes like size or position. |
front 13 4. What is conserved during a chemical reaction? | back 13 The total mass of the reactants and products - Explanation: Atoms don’t disappear or appear; their total mass stays the same (conservation of matter). |
front 14 5. What is a reactant? | back 14 A substance that undergoes a chemical change - Explanation: Reactants are the starting materials that change during a reaction (e.g., baking soda in a vinegar reaction). |
front 15 6. **What is the primary focus of the Chemical Reactions and Energy unit? | back 15 How chemical reactions release or absorb energy - Explanation: This unit explores how reactions give off or take in energy, like heat or light. |
front 16 7. What type of energy is released or absorbed during a chemical reaction? | back 16 Thermal or light energy - Explanation: Chemical reactions often release or absorb heat (thermal energy) or light (e.g., a glowing fire). |
front 17 8. What makes a reaction exothermic | back 17 It releases heat to the surroundings - Explanation: Exothermic reactions, like burning wood, feel hot because they release heat. |
front 18 9. What is an example of an endothermic reaction? | back 18 Photosynthesis - Explanation: Photosynthesis takes in energy from sunlight to make food, making it endothermic. |
front 19 10. What does a model of energy transfer show? | back 19 How energy moves between the system and surroundings - Explanation: Models show how energy flows, like heat leaving a reaction to warm the air around it. |
front 20 11. What is the anchoring phenomenon in the Metabolic Reactions unit?** | back 20 How food provides energy for the body - Explanation: This unit focuses on how food’s chemical energy fuels body activities through reactions. |
front 21 12. What is the primary source of energy for metabolic reactions in the body?** | back 21 Chemical energy stored in food - Explanation: Food contains energy that the body uses through metabolic reactions like cellular respiration. |
front 22 13. Which process breaks down food to release energy? | back 22 Cellular respiration - Explanation: Cellular respiration breaks down glucose with oxygen to release energy for the body. |
front 23 14. **What are the main products of cellular respiration?** | back 23 Carbon dioxide and water - **Explanation**: Cellular respiration uses glucose and oxygen, producing carbon dioxide and water as waste. |
front 24 15. **What role does oxygen play in cellular respiration?** | back 24 It is a reactant that helps break down glucose - **Explanation**: Oxygen is needed to break down food molecules to release energy. |
front 25 16. **What is a product of a chemical reaction?** | back 25 A substance formed as a result of the reaction - **Explanation**: Products are the new substances made after a reaction (e.g., water from burning hydrogen). |
front 26 17. **What happens to the atoms in a chemical reaction?** | back 26 They are rearranged to form new substances - **Explanation**: Atoms don’t vanish or appear; they just form new combinations. |
front 27 18. **What is activation energy?** | back 27 The energy needed to start a chemical reaction - **Explanation**: Activation energy is like the “push” needed to get a reaction going (e.g., striking a match). |
front 28 19. **Which of the following is a metabolic reaction in the body?** | back 28 Digesting food to produce energy - **Explanation**: Metabolic reactions, like digestion, happen in living things to provide energy. |
front 29 20. **What is the purpose of modeling in the Chemical Reactions and Matter unit?** | back 29 To explain how atoms rearrange during a reaction - **Explanation**: Models help show how atoms in reactants rearrange to form products. |
front 30 Open-Response Questions: Tips and Example Answers Question 21: Explain how the Chemical Reactions and Matter unit uses the phenomenon of a burning match to help students understand chemical reactions. Include at least two specific concepts (e.g., reactants, products, conservation of matter) and how they relate to the phenomenon. - **Tips**: - Start by describing the burning match and why it’s a good example of a chemical reaction (it changes wood into new substances). - Pick two concepts (e.g., reactants/products, conservation of matter) and explain them clearly. - Connect each concept to the match: What are the reactants? What are the products? How does mass stay the same? - Use simple language and examples to show understanding. | back 30 - **Example Answer**: The burning match helps us understand chemical reactions because it shows how things change into new stuff. One concept is reactants and products. The reactants are the wood on the match and oxygen in the air. When the match burns, they turn into products like ash, smoke, and carbon dioxide gas. This shows a chemical reaction because new substances are made. Another concept is conservation of matter. The atoms in the wood and oxygen don’t disappear when the match burns; they just rearrange to form the products. Even though the match looks smaller, the total mass of the reactants equals the mass of the products, like the gases that go into the air. |
front 31 Open-Response Questions: Tips and Example Answers Question 22: Describe an experiment from the Metabolic Reactions unit that demonstrates how food provides energy for the body. Include the setup, observations, and what the experiment reveals about metabolic reactions. - Tips: - Describe a clear experiment, like burning food in a calorimeter, and explain the setup (e.g., equipment used). - Mention specific observations, like temperature changes, to show what happened. - Explain how the experiment connects to metabolic reactions (e.g., how burning food is similar to cellular respiration). - Keep the explanation simple but include enough detail to show the link to energy. | back 31 Example Answer: In the Metabolic Reactions unit, we did an experiment with a calorimeter to show how food provides energy. We set it up by placing a cheese puff under a can filled with water and lighting the cheese puff on fire. We measured the water’s temperature before and after burning with a thermometer. We observed that the water’s temperature went up, like from 20°C to 25°C, because the burning cheese puff released heat. This experiment shows that food has chemical energy, just like how our bodies use metabolic reactions like cellular respiration to break down food with oxygen. In our bodies, this energy helps us move and grow, similar to how the heat warmed the water. |