All flashcards
Flashcard 1: Is chopping wood a physical or chemical change?
Answer: Physical change. Only size and shape change, not composition.
Flashcard 2: Is souring milk a physical or chemical change?
Answer: Chemical change. Bacteria produce acids that change milk composition.
Flashcard 3: Identify whether dissolving sugar in tea is a physical or chemical change.
Answer: Physical change. Sugar molecules disperse but remain unchanged.
Flashcard 4: Identify whether rusting iron is a physical or chemical change.
Answer: Chemical change. Iron reacts with oxygen to form iron oxide.
Flashcard 5: Is chopping wood a physical or chemical change?
Answer: Physical change. Only size and shape change, not composition.
Flashcard 6: Is souring milk a physical or chemical change?
Answer: Chemical change. Bacteria produce acids that change milk composition.
Flashcard 7: What is combustion?
Answer: A chemical process of burning, involving oxygen and fuel. Oxidation reaction that releases energy as heat.
Flashcard 8: Identify whether crushing a can is a physical or chemical change.
Answer: Physical change. Only shape changes, aluminum composition unchanged.
Flashcard 9: What is a physical property?
Answer: A characteristic that can be observed without changing substance identity. Observable without altering molecular composition.
Flashcard 10: Identify whether bending a metal rod is a physical or chemical change.
Answer: Physical change. Only shape changes, metal composition unchanged.
Flashcard 11: Identify whether bleaching a stain is a physical or chemical change.
Answer: Chemical change. Bleach chemically alters the stain molecules.
Flashcard 12: What is a precipitate in a chemical reaction?
Answer: An insoluble solid formed from a solution. Forms when dissolved ions recombine and crystallize.
Flashcard 13: Identify whether frying an egg is a physical or chemical change.
Answer: Chemical change. Heat denatures proteins in the egg.
Flashcard 14: What is sublimation?
Answer: The transition of a substance from solid to gas without liquifying. Direct phase transition bypassing liquid phase.
Flashcard 15: Is freezing water a physical or chemical change?
Answer: Physical change. Only state changes from liquid to solid.
Flashcard 16: What is a physical change?
Answer: A change affecting the form but not the chemical composition. Only molecular arrangement changes, not identity.
Flashcard 17: Is breaking a glass a physical or chemical change?
Answer: Physical change. Only shape changes, glass composition stays same.
Flashcard 18: Identify whether photosynthesis is a physical or chemical change.
Answer: Chemical change. CO2 and glucose form from light energy and reactants.
Flashcard 19: What is deposition in terms of phase change?
Answer: Gas to solid transition. Vapor condenses directly to solid state.
Flashcard 20: Identify whether evaporating alcohol is a physical or chemical change.
Answer: Physical change. Only state changes from liquid to gas.
Flashcard 21: What is the result of a chemical reaction?
Answer: Formation of new substances with different properties. Products have different molecular structures than reactants.
Flashcard 22: What is the main difference between physical and chemical changes?
Answer: Physical changes do not alter chemical composition; chemical changes do. Chemical composition determines the type of change.
Flashcard 23: What is combustion?
Answer: A chemical process of burning, involving oxygen and fuel. Oxidation reaction that releases energy as heat.
Flashcard 24: What is the law of conservation of mass?
Answer: Mass is neither created nor destroyed in a chemical reaction. Total mass of reactants equals total mass of products.
Flashcard 25: Identify whether rusting iron is a physical or chemical change.
Answer: Chemical change. Iron reacts with oxygen to form iron oxide.
Flashcard 26: Identify whether melting ice is a physical or chemical change.
Answer: Physical change. Only state changes from solid to liquid.
Flashcard 27: What type of change is dissolving salt in water?
Answer: Physical change. Salt molecules disperse but remain chemically unchanged.
Flashcard 28: What are indicators of a chemical change?
Answer: Color change, gas production, temperature change, precipitate formation. These signs indicate new substances are forming.
Flashcard 29: Identify whether digestion of food is a physical or chemical change.
Answer: Chemical change. Enzymes break down molecules into new compounds.
Flashcard 30: Identify whether fermenting grapes is a physical or chemical change.
Answer: Chemical change. Sugars convert to alcohol through enzyme reactions.