Phase Changes
Define the term boiling.
where a liquid changes to a gas
How do particles move in a gas?
rapidly, randomly and in all directions
What happens to the kinetic energy of an object when it moves faster?
its kinetic energy increases
Define the term melting.
where a solid changes to a liquid
Explain what happens to the particles when a liquid is heated and starts to evaporate.
The particles gain kinetic energy, causing them to move faster.
Why do gases have more kinetic energy than solids?
their particles move more freely and rapidly, exhibiting higher average speeds and greater distances between them
Define the term condensation.
where a gas turns into a liquid
Use the particle model to explain why solids keep their shape but liquids do not.
Solids maintain their shape because their particles are held in fixed positions, while liquids flow because their particles can move past each other, taking the shape of their container.
A ball rolls down a hill. Describe how its kinetic energy changes.
Kinetic energy increase
Define the term sublimation.
where a substance transitions directly from a solid to a gaseous state, without becoming a liquid first
When ice melts in your drink, what happens to the particles in the ice?
It gain energy and begin to vibrate more vigorously.
Explain how kinetic energy is related to temperature.
increasing the kinetic energy of a substance's particles increases its temperature, and decreasing kinetic energy decreases the temperature
Define the term deposition.
where a gas directly transforms into a solid, bypassing the liquid phase
Why does heating a solid make it expand?
The increased in heat energy makes the atoms vibrate more vigorously and move further apart
Two cars are moving: one is heavy but slow, the other is light but fast. Which one has more kinetic energy and why?
the car with the higher combined value of mass and squared velocity (speed squared) will have more kinetic energy