All flashcards
Flashcard 1: What is the best model-based explanation for a suction cup sticking to a smooth surface?
Answer: Lower pressure under the cup lets outside air pressure push it on. Removing air creates pressure difference.
Flashcard 2: Which observable effect best supports the claim that air exerts pressure: a book falling or a parachute slowing?
Answer: A parachute slowing due to air pushing upward. Air resistance shows gas particles push on objects.
Flashcard 3: A sealed bag expands after being warmed. Which increased most: particle speed or particle size?
Answer: Particle speed increased most. Temperature affects speed, not particle size.
Flashcard 4: A sealed bottle dents inward after cooling. Which is higher: inside pressure or outside pressure?
Answer: Outside pressure is higher than inside pressure. Cooling reduced inside pressure below atmospheric.
Flashcard 5: Which model best explains a balloon popping when too much air is added: increased or decreased collisions?
Answer: Increased collisions increase pressure until the balloon bursts. Too many collisions exceed balloon's strength.
Flashcard 6: Which change decreases gas pressure in a sealed container: adding gas or removing gas?
Answer: Removing gas decreases gas pressure. Fewer particles mean fewer collisions.
Flashcard 7: What causes a balloon to shrink when air is removed, according to a particle model?
Answer: Fewer particle collisions reduce pressure, so the balloon contracts. Less air means fewer collisions to maintain shape.
Flashcard 8: What causes a balloon to inflate when air is added, according to a particle model?
Answer: More particles collide with the balloon, increasing outward pressure. More particles mean more collisions per second.
Flashcard 9: What observable effect shows that air is matter even though it is invisible?
Answer: It takes up space and can push on objects. Matter has mass and volume, creating observable forces.
Flashcard 10: What does a particle model show about the spacing of particles in a gas?
Answer: Gas particles are far apart with lots of empty space. Unlike liquids/solids, gas particles have large gaps between them.
Flashcard 11: Which property of gases explains why a gas fills the entire shape of a container?
Answer: Gases expand to fill all available space. Particles spread out to occupy any container shape.
Flashcard 12: What does a particle model show about how gas particles move?
Answer: They move freely and randomly in all directions. No forces hold them in place, so they move constantly.
Flashcard 13: What is the scientific meaning of gas pressure in a closed container?
Answer: Force from gas particle collisions pushing on container walls. Particles constantly hit walls, creating measurable force.
Flashcard 14: Identify the correct statement: gas particles collide with walls often or never in a container?
Answer: Gas particles collide with walls often. Continuous collisions create pressure.
Flashcard 15: Which change increases gas pressure in a sealed container: heating it or cooling it?
Answer: Heating it increases gas pressure. Heat makes particles move faster and collide more.
Flashcard 16: What observable effect best shows that gases can be compressed?
Answer: Air in a syringe can be pushed into a smaller volume. Particles can be forced closer together.
Flashcard 17: What is the best model-based explanation for wind pushing a flag outward?
Answer: Moving air particles collide with the flag and exert pressure. Wind is moving air particles hitting objects.
Flashcard 18: What is the best model-based explanation for drinking through a straw?
Answer: Lower pressure in the straw lets air pressure push liquid up. Sucking removes air, creating pressure difference.
Flashcard 19: What is the best model-based explanation for a sealed bag shrinking in a freezer?
Answer: Cooler gas moves slower, decreasing collisions and pressure. Cold slows particles, reducing collision frequency.
Flashcard 20: What is the best model-based explanation for a sealed bag puffing up in the sun?
Answer: Warmer gas moves faster, increasing collisions and pressure. Heat energy makes particles move and collide more.
Flashcard 21: What causes a balloon to expand when more air is added, using the particle model?
Answer: More collisions increase outward pressure, stretching the rubber. Increased collisions push walls outward against elastic force.
Flashcard 22: Which property of gases explains why air in a syringe can be compressed but water cannot?
Answer: Gases are compressible because particles are far apart. Large spaces between particles allow them to be pushed closer.
Flashcard 23: Which statement best explains why a balloon becomes firm as it is inflated?
Answer: More gas particles increase pressure on the balloon walls. More particles mean more collisions pushing outward.
Flashcard 24: Which observable effect best shows that a gas takes up space inside a container?
Answer: It fills the entire container volume. Gas particles spread to occupy all available space.
Flashcard 25: Which change usually increases gas pressure in a sealed container: heating or cooling?
Answer: Heating. Higher temperature increases particle speed and collision force.
Flashcard 26: What is the particle-model reason that heating a gas in a sealed bottle increases pressure?
Answer: Particles move faster, causing more frequent and harder collisions. Kinetic energy increases with temperature, boosting impacts.
Flashcard 27: Identify the observable effect when a sealed bag of air is warmed: does it expand or shrink?
Answer: It expands. Warmer particles push harder, stretching flexible walls.
Flashcard 28: What model describes a gas as tiny particles moving randomly and colliding elastically?
Answer: The particle (kinetic) model of gases. Particles move freely, collide without sticking, and bounce off.
Flashcard 29: What is gas pressure in a container, in terms of particle collisions with surfaces?
Answer: The push from gas particles colliding with container walls. Particles constantly hit walls, creating force per area.
Flashcard 30: What is the model-based reason a marshmallow expands when air pressure around it decreases?
Answer: Gas in its bubbles pushes outward more than the lower outside pressure. Trapped gas pressure exceeds reduced external pressure.