Chapter 4 Sec. 2 Changes of State

Cameron Keehley

Chris Day

Xavier Alfaro

Dylan Van Note

Changing States of Matter- Brainpop

• https://jr.brainpop.com/science/matter/changingstatesofmatter/

Thermal Energy

• Energy- ability to do work or cause change .

• Kinetic Energy- energy of motion. An object with more kinetic energy, the particles move faster and farther apart. An object with less kinetic energy, the particles move slower and stay closer together.

• Thermal Energy- total kinetic energy and potential energy of the particles. The warmer the substance, the more thermal energy.

• Temperature- average kinetic energy of individual particles.

• Thermal=Total/ Temperature=Average

• Heat- movement of thermal energy from higher temperature to lower temperature

Specific Heat• Amount of heat required to raise temperature of a 1g of a substance 1 Degrees Celsius

•Metals and sand have low specific heat. Water has a high specific heat.

Changes Between Solid & Liquid States

• Change of State- matter can change states when thermal energy is absorbed of released. Amorphous solids get softer when heated.

• Melting- change from solid to liquid.

• Melting Point- temperature at which change occurs.

• Freezing- change from liquid to solid. Liquids cool, particles slow, crystals form

• Freezing Point- temperature at which change happens.

• Particles in liquids have more energy than particles in solids

Changes Between Liquid & Gas States

•Sublimation- surface particles gain enough energy to become a gas.

•Dry Ice- When dry ice becomes gas, it absorbs thermal energy from water vapor.

Changes Between Liquid & Gas States

• Vaporization- change from liquid to gas.

• Temperature has no change. Substance gains thermal energy. Particles move faster and turn into gas. It takes place below surface of liquid.

• Water boils at 100 Degrees Celsius

Location of Molecules

• Faster particles evaporate, slower particles stay

• Perspiration- cooling effect

• Condensation- change of matter from gas to liquid

• Temperature doesn’t change. There is a decrease in energy.

• Condensation shows up on outside of glass.

Follow-Up