Aim: What are the States of Matter

Nature of Gases Gases: No definite shape or volume Particles are very far apart and move all over Total disorder- particles move in all directions

Gas Pressure Gas particles exert pressure when they collide with walls of the container they are in.

Atmospheric pressure Atmospheric pressure results from the collisions of atoms and molecules in air with objects. SI unit for pressure is the pascal (Pa). Other units are atmosphere (atm) and millimeters of mercury (mm Hg). Standard pressure is1 atm = 760 mm Hg = 101.3 kPa

Atmospheric pressure Atmospheric pressure is greater at sea level.

Balloon Suction Demo Answer the following questions during the demo: 1. What is air? 2. What is air pressure? 3. What do you think happens when air is heated up? 4. At what point do you think the air pressure in the flask decreased? 5. How can we get the balloon out of the flask?

Answers to demo 1. What is air? Air is the mix of gases in our atmosphere. 2. What is air pressure? Air pressure is the pressing, forcing, and moving of air as it interacts with things around it. 3. What happens when air is heated up? When air gets warmer, it expands and takes up more space. 4. At what stage do you think the air pressure in the flask was reduced? As the lit paper extinguished and the air began to cool. 5. How can we get the balloon out of the flask? Heating the flask…anything to increase the pressure in the flask again.

Kinetic Energy and Temperature What is energy? The capacity to do work or produce heat What is Kinetic Energy (K.E.)? The energy an object has because of its motion.

Kinetic Energy and Temperature Temperature is a measurement of the average kinetic energy of atoms or molecules.

Kelvin Temperature Scale (table T) 1. K = 273 + oC 2. oC = K - 273 3. 0 K = absolute zero Standard temperature = 0 oC = 273 K

Nature of Liquids Liquids have: Definite volume and take the shape of the container Particles are still close together and move while touching each other No regular pattern or arrangement of particles.

Evaporation Evaporation is when liquid changes into gas.

Nature of Solids Solids have: Definite shape and volume Particles are close together in fixed positions, vibrate but do not move. Crystalline structure

Crystal Structure Crystals have particles arranged in a regular geometric pattern

Allotropes Allotropes are two or more molecular forms of the same elements in the same physical state. Allotropes have different properties because their structures are different.

Examples of Allotropes Two allotropes of oxygen (dioxygen, O2, and ozone, O3), can both exist in the solid, liquid and gaseous states. Coal and diamonds are allotropes of carbon

Changes of State Gas  liquid = condensation Liquid  gas = evaporation Solid  liquid = melting Liquid  solid = freezing Gas  solid = deposition Solid  gas = sublimation

Summary 1. Describe the behavior of particles in the solid, liquid, and gas phase. 2. Sketch how the particles would look like in each phase.