3.1 Definitions States of Matter

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1 3.1 Definitions States of Matter WORDS FOR DEFINITIONS YOU NEED ARE IN RED Phase /state Solid Liquid Gas Elastic Collision Kinetic Theory Volume Pressure Temperature Absolute Zero Temp Celsius Kelvin Fahrenheit Rankine Scales Liters Meters 3 Newtons Pascals Force Atmosphere Anomaly Fluid Compressible Incompressible (the unit) Fluid Fluid Phase /state the physical condition of a substance, the 3 common phases of substances are solid, liquid and gas (over 99%) Plasma is a fourth and more rare phase, seen in fire, and lightening and the sun. BEC (Bose Einstein condensate) a very dense state when the temperature approaches -273 C Solid - a substance which has a definite shape (one that does not change easily) and volume. Solids keep their shape. Solids are incompressible. Density does not change. Since its volume cannot change its also cannot change. EXAMPLES: Anything made of metal, ice, wood, etc. Liquid - a substance which does not have a definite shape but does have a definite volume. Liquids move to the bottom of their containers and take their shape. All Liquids (oil, water, alcohol) are so nearly incompressible they can be considered incompressible. Density does not change. Since its volume cannot change its also cannot change. EXAMPLES: Liquid water, oil, gasoline,

2 Gas a substance with neither definite shape nor volume. A gas expands to fill all parts of their containers. SOLIDS LIQUIDS GASES Solid Liquid Gas Settles to bottom of Shape Definite container Volume Definite Definite Compressible Density (Normal Substances) Density (Water) Kinetic Energy Temperature Bond Strength Structure Constant or Definite Constant or Definite Expands to fill all parts of container Changes with Conditions of Pressure and Temp

3 Fluid a substance which flows (liquids and gasses) Compressible Fluid a gas, these can be compressed by a pressure. Incompressible Fluid a liquid

4 ANOMALY: deviation from the common rule : IRREGULARITY Why is water an anomaly? The most dense state of water is as a liquid. Water is important to life on Earth for many reasons. What does it affect in nature? Ice floats Ponds freeze from top to bottom rather than bottom to top Freezing on top insulates them so they are less likely to freeze solid This protects fish and other wild life from freezing which would kill them. Skating IDEA under great pressure (under a skate) Solid water favors a more compact arrangement which is this causes skates to have a film of low friction water under them FROG HIBERNATION THE Ice layer protects the pond from freezing all the way to the bottom and killing the fish and frogs and other animals. If the pond froze from bottom to top they would not survive the winter.

5 The variation of density of water with temperature is odd because its maximum is not just before it turns to a solid (32 F or C) but at 4 C. This causes a few interesting situations in a pond.

6 POND FORMS IMPORTANT LAYERS POND TURNOVER -

7 EXPANDING ICE - When pipes freeze or your engine freezes it can break open and cause a problem. Can we design an experiment to show that water expands (is less dense) when it freezes? Someone explain the steps? National Geographic Science of Ice Skating:

8 THE KINETIC THEORY Chapter 3, page 73 Your book has a simplified incomplete version. 1. Gas particles are in constant rapid random motion. 2. Gas particles are so small that they may be considered to have NO VOLUME relative to the empty space that surrounds them. Mathematically: Volume of Particles << Volume of surrounding space 3. Collisions are perfectly elastic. Velocity is unaffected by the collisions or motion of the other particles. Before collision Collision After collision Velocity before collision = Velocity after collision 4. The average velocity of the particles is directly related to the temperature of the gas. Low Temp Gas Low Velocity Particles High Temp Gas High Velocity Particles

9 THE KINETIC THEORY ONLY WORKS FOR GASES Gas: HIGH TEMPERATURE HIGH KINETIC ENERGY HIGH VELOCITY NO BONDS BETWEEN PARTICLES LOW DENSITY AS GAS COOLS COLLISIONS BECOME STICKY WEAK BONDS FORM Liquid: MEDIUM TEMPERATURE MEDIUM KINETIC ENERGY MEDIUM VELOCITY WEAK BONDS BETWEEN PARTICLES INCREASED DENSITY EVENTUALLY ENOUGH VIBRATION BREAKS THE RIGID SPRING-LIKE BONDS (ENERGY REQUIRED TO MELT ICE TO WATER) Solid: LOW TEMPERATURE LOW KINETIC ENERGY LOW VELOCITY STRONG BONDS BETWEEN PARTICLES HIGHEST DENSITY

10 KINETIC ENERGY STUDY GUIDE COMPLETE FILLING IN OUR TABLE. Solid Liquid Gas Settles to bottom of Expands to fill all parts of Shape Definite container container Volume Definite Definite Compressible Density (Normal Substances) Density (Water) Kinetic Energy Temperature HIGHEST Constant or Definite Incompressible IN BETWEEN* Constant or Definite IN BETWEEN Constant or Definite Incompressible HIGHEST* Constant or Definite LOWEST Changes with Conditions of Pressure and Temp. Compressible LOWEST Changes with Conditions of Pressure and Temp. Incompressible Incompressible Compressible LOWEST IN BETWEEN HIGHEST LOWEST IN BETWEEN HIGHEST Bond Strength Structure HIGHEST STRENGTH BONDS HIGHEST Orderly crystal structure WEAK BONDS LOOSE STRUCTURE NO BONDS NO STRUCTURE * Water is the anomaly because its highest density is as a liquid rather than a solid.

11 Study Guide for Phases of Matter. Fill this in as we go through the notes. This is not homework. Shape Volume Density (Normal Substances) Density (Water) Kinetic Energy Temperature Bond Strength Structure Solid Liquid Gas

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