All flashcards
Flashcard 1: Which model revision fits the evidence that air can be compressed in a closed syringe?
Answer: Show gas particles moving closer together under pressure. Compression reduces space between particles without changing their number.
Flashcard 2: What does it mean to revise a scientific model based on evidence?
Answer: Change the model so it matches new observations and data. Models must be updated when new data contradicts them.
Flashcard 3: What is the best definition of evidence in science?
Answer: Observations or measurements used to support or change an idea. Evidence provides factual basis for scientific conclusions.
Flashcard 4: What is a particle model of matter used to represent?
Answer: Matter as tiny particles with spaces and motion. Shows matter consists of moving particles with empty space between them.
Flashcard 5: Which state of matter has particles far apart and moving freely: solid, liquid, or gas?
Answer: Gas. Gas particles have maximum separation and freedom of movement.
Flashcard 6: What should a model of air include to match the evidence that air takes up space?
Answer: Air must be shown as matter that occupies volume. Evidence shows air fills containers, proving it has volume.
Flashcard 7: Identify the model change supported when a balloon expands as it fills with air.
Answer: Add that air has particles that take up space inside the balloon. Balloon expansion proves air particles occupy space.
Flashcard 8: Identify the model change supported when air can be trapped in a syringe with the tip closed.
Answer: Include that air is matter that can be contained. Trapped air proves it's matter that can be held in containers.
Flashcard 9: What model revision fits the evidence that a basketball feels harder after pumping more air in?
Answer: More air particles increase pressure inside the ball. More particles in same space creates higher pressure.
Flashcard 10: Which model revision matches the evidence that a sealed chip bag puffs up at high altitude?
Answer: Lower outside pressure lets trapped gas expand. Reduced external pressure allows internal gas to expand.
Flashcard 11: What does it mean for a substance to dissolve in water?
Answer: Its particles spread evenly among water particles. Solute particles distribute uniformly throughout the solvent.
Flashcard 12: What is a solution?
Answer: A mixture where a solute is evenly dissolved in a solvent. Solutions have solute particles evenly distributed in solvent.
Flashcard 13: In saltwater, what is the solute?
Answer: Salt. The solute is the substance being dissolved.
Flashcard 14: In saltwater, what is the solvent?
Answer: Water. The solvent is the substance doing the dissolving.
Flashcard 15: Which model revision matches the evidence that salt “disappears” but the water tastes salty?
Answer: Show salt particles still present, spread throughout the water. Dissolved salt remains as particles distributed in water.
Flashcard 16: Which model revision matches the evidence that dissolved sugar cannot be removed with a strainer?
Answer: Sugar particles are too small and pass through with water. Dissolved particles are smaller than strainer openings.
Flashcard 17: What model revision matches the evidence that stirring makes sugar dissolve faster?
Answer: Stirring increases particle mixing and contact. Motion helps particles collide and mix more quickly.
Flashcard 18: What model revision matches the evidence that warmer water dissolves sugar faster than cold water?
Answer: Higher temperature means faster particle motion and mixing. Heat increases particle speed, promoting faster dissolving.
Flashcard 19: Which model revision fits the evidence that bubbles form when soda is opened?
Answer: Dissolved gas escapes as pressure drops and forms bubbles. Opening releases pressure that kept gas dissolved.
Flashcard 20: What revision is supported if a model shows dissolved salt settling at the bottom of a clear solution?
Answer: Correct it: dissolved particles stay evenly mixed, not settled. True solutions don't settle; particles remain dispersed.
Flashcard 21: Which model revision fits a straw wrapper sticking to a wet cup: does air pressure push on objects?
Answer: Yes, air pressure pushes on objects from all directions. Air molecules constantly collide with surfaces.
Flashcard 22: Which model revision fits soda going flat after opening: does lower pressure keep more or less gas dissolved?
Answer: Lower pressure keeps less gas dissolved. High pressure forces more gas to stay dissolved.
Flashcard 23: Which everyday observation is evidence that air has mass: a full ball weighs more or less than a deflated ball?
Answer: A full ball weighs more. Air particles have mass that adds to the ball's weight.
Flashcard 24: Identify the model revision from salty water evaporation: does dissolved salt evaporate with the water?
Answer: No; water evaporates but dissolved salt remains behind. Only water molecules escape; salt particles remain.
Flashcard 25: Which statement is the correct model for dissolving sugar: sugar disappears or sugar particles spread out in water?
Answer: Sugar particles spread out evenly in the water. Dissolving separates sugar into invisible particles.
Flashcard 26: What is the best model-based explanation for fish needing oxygen from water?
Answer: Oxygen gas is dissolved in water and can be taken in by gills. Fish extract dissolved oxygen molecules from water.
Flashcard 27: Which option is the best evidence that gases can dissolve: bubbles appear in water after opening a soda bottle?
Answer: Yes; escaping bubbles show gas was dissolved in the liquid. Bubbles form when dissolved gas comes out of solution.
Flashcard 28: Which model revision fits shaking a soda then opening: does agitation make dissolved gas leave faster or slower?
Answer: Agitation makes dissolved gas leave faster. Shaking provides energy for dissolved gas to escape.
Flashcard 29: Which option is evidence that air takes up space: a flat balloon or an inflated balloon?
Answer: An inflated balloon. The balloon expands because air particles push outward.
Flashcard 30: What is the particle-model claim about air that explains why it can be compressed?
Answer: Air particles have spaces between them that can be reduced. Compression works because particles can move closer together.