Particle Theory
What does the Particle Theory say all matter is made of?
Tiny particles.
If the particles in an object are moving faster, what happens to their kinetic energy?
It increases.
What does temperature actually measure about particles?
The average kinetic energy of the particles.
Why do particles expand when heated?
Particles move faster and spread farther apart.
What are the three types of heat transfer?
Conduction, convection, and radiation.
In which state of matter do particles move the fastest?
Gas.
What is the main difference between kinetic energy and thermal energy?
Kinetic energy is the energy in motion of individual particles, while thermal energy is the total energy of all particles in a substance.
Why does adding heat to a substance usually increase particle motion?
Heat transfers energy to particles, increasing their kinetic energy.
Why might a jar lid loosen when you run it under hot water?
The metal lid expands slightly due to the heating.
Which type of heat transfer occurs through direct contact?
Conduction.
How are particles arranged in a solid?
Very close together and vibrating in place.
A hot cup of tea and a warm bathtub have different temperatures. Which one might have more thermal energy, and why?
The bathtub, because it has far more particles even though the temperature is lower.
Why might a metal playground equipment feel colder than plastic even though both are the same temperature outside?
Metal conducts heat away from your hand faster.
Why do engineers leave small gaps between concrete sections of sidewalks and bridges?
To allow materials to expand in warm temperatures.
Which type of heat transfer occurs in liquids and gases through movement?
Convection.
What happens to particles when matter is heated?
They move faster and spread farther apart.
Two metal blocks are at the same temperature. One block is twice as large as the other. Which one has more thermal energy?
The larger block because it has more particles.
A pot of water and a small cup of water are both at 60 degrees Celsius. Which one has particles moving faster?
Neither. The particles are moving at the same average speed because the temperature is the same.
What could happen if train tracks had no space for thermal expansion?
They could bend or buckle when temperatures increase.
Which type of heat transfer travels through empty space?
Radiation.
Why can gases be compressed but solids cannot?
Gas particles have lots of space between them, while solid particles are tightly packed.
Why can two objects have the same temperature but different thermal energy?
Because thermal energy depends on both temperature and the number of particles.
Two thermometers are placed outside on a cold day. One is in direct sunlight and one is in the shade. The thermometer in the sun reads a higher temperature. Why?
The thermometer in the sub absorbs radiation from the Sun causing its particles to gain kinetic energy and increasing the temperature reading.
Why is expansion usually smaller in solids than in gases?
Solid particles are already close together and strongly held in place.
Explain why heating vents are often placed near the floor in buildings/rooms.
Warm air rises, allowing heat to circulate through the room.