a metal entrance door swings freely in the winter, but when the weather turns warm, the door sticks and seems too big for the door frame. Using your knowledge of the particle theory, explain what is happening.
The door is made of metal and the frame is probably made of wood. Metal expands more than does wood when it is warm, so the metal door actually gets bigger and tightens up in the frame. From a particle theory perspective, the metal door expands more than does the wooded frame because its particles are closer together and pushes other particles more as they move or vibrate more and faster as they get warm.
