DOMAIN 4 ENERGY TRANSFORMATIONS

SOLIDS, LIQUIDS, AND GASES Kinetic Theory

1. What is the kinetic theory? The theory states that all matter is made up of particles that are in constant, random motion The particles collide with each other and the walls of their containers

3. What is the average kinetic energy of molecules? The temperature of a substance, or the average of how fast the particles are moving The lower the temperature, the slower the particle motion

4. How are particles arranged in the solid state of matter? They are closely packed together in a specific type of geometric arrangement They are in constant motion (vibrate in place)

5. How are liquid particles arranged in the liquid state of matter? Liquid particles have more space between them, allowing them to flow and take the shape of their container

6. How are particles arranged in the gaseous state of matter? They are spread evenly through their container in the process of diffusion They are in constant motion colliding with each other and with their container

7. What happens to temperature during a phase change? Temperature remains constant during the phase change The addition of energy during a phase change (melting, evaporation, or sublimation) is used to overcome the attractive forces between molecules; not to raise the temperature Only after the phase change is complete will the temperature begin to change

8. What is a phase change diagram? A diagram showing what happens to temperature and thermal energy during a phase change

9. What is the plasma state of matter? The state of matter consisting of high- temperature gas with balanced positively and negatively charged particles

10. What is thermal expansion? An increase in the size of a substance when the temperature increases The size of a substance will then decrease when the temperature decreases.

Expansion joints in bridges let them expand and contract without affecting traffic. This one is part of a wooden bridge over the Seine River in Paris. The expansion and contraction of long bridges can be enormous. The length of the Bay Bridge between San Francisco and Oakland has shrunk over 4 feet in very cold weather.

Boiling water poured into this thick-walled mug fractured it, because the inside expanded so much more rapidly than the outside.

Thermal expansion on a hot July day in New Jersey caused this train to derail.

EXCEPTION: Ice floats since its density is only g/cm3.

6. What is viscosity? A liquid’s resistance to flow Molecular structure determines a fluid’s viscosity. Increased temperature will lower viscosity. Honey has a high viscosity