Changes of State
100: What is a physical change?
100: A physical change is a change in a substance's form, not its chemical makeup.
100: Define thermal energy.
100: Thermal energy is the total energy of all the particles in an object.
100: What happens to gas particles when pressure increases?
100: When pressure increases, gas particles are forced closer together.
100: What observations might indicate a change of state?
100: Observations like melting or freezing show a change of state.
100: How is energy transferred when ice melts?
100: When ice melts, energy is transferred from the environment to the ice.
200: Name three states of matter.
200: Three states of matter are solid, liquid, and gas.
200: How does temperature relate to kinetic energy?
200: Temperature is a measure of the average kinetic energy of particles in a substance.
200: How does elevation affect air pressure?
200: As elevation increases, air pressure decreases.
200: How can you identify condensation?
200: You can identify condensation by water droplets forming on a cold surface.
200: What role does kinetic energy play in changes of state?
200: Kinetic energy helps particles move and change state.
300: What is melting?
300: Melting is the process where a solid turns into a liquid.
300: What is the boiling point?
300: The boiling point is the temperature at which a liquid turns into a gas.
300: Why does water boil at a lower temperature at higher elevations?
300: Water boils at a lower temperature at higher elevations due to lower air pressure.
300: What is an example of sublimation?
300: An example of sublimation is dry ice turning directly into gas.
300: How does thermal energy affect the flow of lava?
300: Thermal energy keeps lava flowing by preventing it from solidifying.
400: What is condensation?
400: Condensation is when gas turns into a liquid.
400: Explain the difference between boiling and evaporation.
400: Boiling occurs throughout a liquid, while evaporation happens only at the surface.
400: Explain why cooking times differ at sea level vs. higher elevations.
400: Cooking times are longer at higher elevations because lower air pressure slows boiling.
400: Describe what happens to water as it freezes.
400: As water freezes, its molecules slow down and arrange into a solid structure.
400: Describe how snow changes when exposed to sunlight.
400: Snow melts and may turn into water when exposed to sunlight.
500: What happens during evaporation?
500: During evaporation, a liquid changes into a gas.
500: How does adding thermal energy affect particle movement?
500: Adding thermal energy makes particles move faster and spread out.
500: What happens to the state of matter when pressure is decreased?
500: When pressure is decreased, matter can expand or change state, like gas forming from a liquid.
500: What evidence supports the change of state from liquid to solid?
500: Evidence of a change from liquid to solid includes the hardening of the material, like water turning into ice.
500: What can you infer about the energy transfer when glass is heated?"
500: When glass is heated, you can infer that energy is being absorbed, causing the glass to expand or melt.