Presentation on theme: "Monday, Oct. 5 th Agenda Collect Ozone Worksheet Go over Sec 2.1 review Sec. 2.2: Matter and Energy –Kinetic theory –States of matter –Changes of state."— Presentation transcript:
Monday, Oct. 5 th Agenda Collect Ozone Worksheet Go over Sec 2.1 review Sec. 2.2: Matter and Energy –Kinetic theory –States of matter –Changes of state –Laws: Conservation of mass Conservation of energy Air pressure demos
Section 2.2 Matter and Energy Kinetic Theory 1.All matter is made of atoms and molecules that act like tiny particles. 2.These tiny particles are always in motion. The higher the temperature, the faster the particles move. 3.At the same temperature, more massive (heavier) particles move slower than less massive (lighter) particles.
Solids Particles are in a fixed position but can vibrate slightly around a fixed location. Particles are held closely together by strong attractions. Solids have a rigid structure.
Liquids Particles are closely packed together, but they can still slide past one another. Attraction between particles not as strong as in a solid. Liquids can spread out on their own and will take the shape of the container that they are in. A liquid is considered a fluid because it can flow.
Gases Particles are in constant motion and rarely stick together. They want to be far apart from each other. Gases exert pressure on the container that they are in. Gases are considered a fluid because they flow.
Solids, Liquids and Gases Properties SolidLiquidGas -particles in fixed position, close together -particles vibrate only slightly -strong attractions between particles -rigid structure -particles closely packed -particles can slide past one another -attraction not as strong as solid -takes shape of container -fluid -particles in constant motion -particles very far apart -exerts pressure on container -fluid
Which letter represents a: 1. solid 2. liquid 3. gas
What is pressure? Pressure is defined as the force exerted per unit area of a surface. Gases exert pressure. The gas in a balloon is pushing out against the walls of the balloon.
What is viscosity? Viscosity is determined by the attraction between particles. The stronger the attraction, the more slowly the liquid will flow and the higher the viscosity will be. Maple syrup has a higher viscosity than water.
Energy’s Role Energy is the ability to change or move matter. Energy is transferred in all changes of state.
Changes of State Evaporation: the change of a substance from a liquid to a gas –Ex: a dish of water on a windowsill will evaporate in the sun Condensation: the change of a substance from a gas to a liquid –Ex: water molecules in the air condensing on your glass of soda on a hot, humid day Sublimation: the change of a substance from a solid to a gas. –Dry ice, solid carbon dioxide, changes from a solid into a gas.
Law of Conservation of Mass Mass cannot be created or destroyed.
Law of Conservation of Energy Energy cannot be created or destroyed.
Vacuum pack the students? Yes, that’s what I said. Air pressure is pushing down on us all the time, every day. If we evacuate the air in a garbage bag to create a vacuum, we can actually feel the effects of the air pressure on our bodies. Who wants to try??