State Changes
What is the name of the process when a solid becomes a liquid?
melting
Which state of matter has a definite shape and definite volume?
Solid
What happens to particles in a solid when heat is added
They vibrate faster and may move farther apart, which can lead to melting.
Which of these is a liquid at room temperature: water, iron, or oxygen?
Water
Give one example of a gas commonly found in air
Oxygen or nitrogen
What do we call the process when a liquid becomes a gas at the surface of a liquid?
evaporation
Which state of matter has no definite shape but has a definite volume?
Liquid
Name one everyday example of a solid and one property that shows it is a solid.
Example: Ice — holds its shape; Example answers may vary.
What is condensation?
The process when a gas changes into a liquid
What is condensation (brief definition)?
Gas → liquid
What is the term for a solid changing directly into a gas without becoming a liquid?
Sublimation
Which state of matter has no definite shape and no definite volume?
Gas
What is freezing?
The process when a liquid becomes a solid
Explain why liquids take the shape of their containers but keep the same volume.
Liquid particles are close together so they stay in contact and keep volume, but they can slide past each other so they change shape to match the container.
If you heat a fixed amount of gas in a balloon (and the balloon can expand), what happens to the volume of the gas?
The volume increases
What is deposition?
The process in which a gas changes directly into a solid
For each state (solid, liquid, gas), give one word that describes how its particles are arranged or move
Solid — tightly packed/vibrate; Liquid — close/move past each other; Gas — far apart/move rapidly
Describe why solids keep their shape using particle behavior.
Because the particles are tightly packed and vibrate mostly in place, keeping the solid’s shape.
What is boiling and how is it different from evaporation?
Boiling is when a liquid turns to gas throughout the liquid at its boiling point; evaporation is when liquid becomes gas only at the surface, below the boiling point.
Describe particle spacing and motion in a gas in terms a 6th grader can understand.
Particles are far apart and move quickly in all directions, so gases fill their container.
Explain how adding thermal energy (heat) affects particle motion and can cause a phase change.
Adding thermal energy makes particles move faster and spread out; if they gain enough energy, the substance can change from solid → liquid (melting) or liquid → gas (evaporation/boiling).
How does decreasing temperature affect particle motion and the spacing between particles?
Decreasing temperature makes particles move more slowly and come closer together, which can cause phase changes like gas → liquid (condensation) or liquid → solid (freezing).
A metal rod is heated at one end. Describe what happens to the particles in the heated region and how that could lead to a change of state if temperature keeps increasing.
Particles in the heated region gain energy and vibrate faster, move slightly farther apart; if energy is high enough, the metal can melt (solid → liquid).
A sealed bottle of water is warmed until bubbles form throughout the liquid. What process is occurring, and why do bubbles form inside the liquid?
Boiling — bubbles form because the liquid is turning into gas throughout as it reaches its boiling point; vapor bubbles rise to the surface
Explain how a change in temperature can cause condensation to form on a cold glass of water.
Warm water vapor in the air cools when it touches the cold glass; cooling makes vapor particles slow and come closer together, changing from gas to liquid droplets (condensation).