Solids, Liquids and Gases Chapter 16 Solids, Liquids and Gases

Kinetic Theory Explains how particles in matter behave. Three assumptions: 1. All matter is composed of small particles (atoms, molecules, and ions). 2. These particles are in constant, random motion. 3. These particles are colliding with each other and the walls of their container.

Kinetic Theory Imagine a room filled with tiny bouncing ping pong balls. That is what atoms are like! A very small amount of energy is lost with each collision.

Forces holding particles together Thermal Energy Thermal energy = Kinetic energy + Potential energy Moving Energy Forces holding particles together

Temperature Temperature: the measure of average kinetic energy Quick definition: How fast are the particles moving? Absolute Zero: no more thermal energy can be removed; particles barely moving at all. -273.15 °C or 0 K (kelvin)

States of Matter Solid Liquid Gas Freezing Boiling

Chemical or Physical?

Chemical & Physical Properties Chemical Properties: How a substance reacts. Examples: Flammability, reactions to light Changes into a new substance during the reaction. Physical Properties: Characteristics you can observe. Examples: Color, boiling point, magnetic Doesn’t change what the substance is.

Solid State Particles packed tightly together and constantly vibrating in place. Form a geometric arrangement, which give it specific chemical and physical properties. Solids have their own shape and a definite shape and volume

Liquid State Particles packed tightly together, but are able to move around more freely. Liquids can flow; their particles can slide past each other. Liquids have a definite volume, but take the shape of their container.

Gas State Particles have enough kinetic (moving) energy to separate and spread far apart or contract. Gases do not have a fixed volume or shape. They fill up the space they are in.

Vaporization A particle has enough kinetic (moving) energy to escape from other particles. 2 ways: Evaporation: happens on surface of a liquid at room temperature Boiling: happens throughout liquid at a specific temperature.

Boiling Point To become a gas, the pressure of a vapor in the liquid must be higher than the pressure of the air on the surface. Heat of vaporization: energy required to change a liquid to a gas.

Diffusion Diffusion: Spreading of particles throughout a given volume unit they are evenly distributed. Example: spraying perfume in a room http://highered.mcgraw- hill.com/sites/0072495855/student_view0/chapter2 /animation__how_diffusion_works.html

Adding energy changes the state of matter! **Sketch picture!

Heating Curve of a liquid **Sketch picture!

Plasma Most common state of matter in the universe. Plasma: matter made of + and – charged particles, but is neutral overall. The collisions are very intense and cause electrons to be taken away. Examples: the sun, lightening bolts, neon and fluorescent tubes.

Behavior of Gases Pressure = Force/Area (P = F/A) Unit: Pascals (Pa) = 1 N/m2 At sea level, atomospheric pressure = 101.3 kilopascals (kPa) **Sketch picture & chart !

Behavior of Gases Balloons stay inflated because of the atoms colliding with the walls of the container. If you add air to the balloon, there are more air particles. Therefore, more collisions are occurring and the container expands.

Boyle’s Law

Boyle’s Law ↓ volume = ↑pressure (constant temperature)

Boyle’s Law P1V1 = P2V2 Example: P1V1 = P2V2 100 * 10 = 50 * V2 A balloon has a volume of 10.0 L at a pressure of 100 kPa. What will the new volume be when the pressure drops to 50 kPa? P1 = V1 = P2 = V2 = P1V1 = P2V2 100 * 10 = 50 * V2 1000 = 50 * V2 1000 = 50* V2 50 50 100 kPa 10.0 L 20 L = V2 50 kPa 20 L

Pressure-Temperature Law What happens when you heat a container that can’t change shape? ↑ temperature = ↑ pressure Pressure builds until the container can’t hold it any more and it explodes.

Charles’s Law

Charles’s Law ↑ temperature = ↑ volume (constant pressure)

Charles’s Law V1/T1 = V2/T2 (temp must be in kelvin) Example: A balloon has a volume of 2.0 L at a temperature of 25ºC. What will the new volume be when the temperature drops to 10ºC? V1 = T1 = V2 = T2 = V1/T1 = V2/T2 2.0 = V2 298 283 298 * V2 = 2.0 * 283 2.0 L V2 = 2.0 * 283 298 25ºC + 273 = 298 K 1.9 L V2 = 1.9 L 10ºC + 273 = 283 K