KINETIC THEORY Turk *

KINETIC THEORY Kinetic Theory states that the tiny particles in all forms of matter are in constant motion. Kinetic refers to motion Helps you understand the behavior of solid, liquid, and gas atoms/molecules as well as the physical properties

KINETIC THEORY 3 Principles of Kinetic Theory All matter is made of tiny particles (atoms) These particles are in constant motion When particles collide with each other or the container, the collisions are perfectly elastic (no energy is lost)

STATES OF MATTER States of Matter Solid Liquid Gas Plasma http://www.plasmas.org/E-4phases2.jpg

SOLIDS Particles are tightly packed and close together Particles do move but not very much Definite shape and definite volume (because particles are packed closely and do not move) Most solids are crystals Crystals are made of repeating patterns The shape of a crystal reflects the arrangement of the particles within the solid

LIQUIDS Particles are spread apart Particles move slowly through a container No definite shape but do have a definite volume Flow from one container to another Viscosity – resistance of a liquid to flowing Honey – high viscosity Water – low viscosity chemed.chem.purdue.edu/.../graphics

GASES Particles are very far apart Particles move very fast No definite shape and No definite volume http://www.phy.cuhk.edu.hk/contextual/heat/tep/trans/kinetic_theory.gif

PLASMA Particles are extremely far apart Particles move extremely fast Only exists above 3000 degrees Celsius Basically, plasma is a hot gas When particles collide, they break apart into protons, neutrons, and electrons Occurs naturally on the sun and stars

TEMPERATURE Temperature is the measure of the average kinetic energy of the particles. 3 Units for Temperature: Celsius Fahrenheit Kelvin Has an absolute zero Absolute lowest possible temperature All particles would completely stop moving

KINETIC ENERGY AND TEMPERATURE Speed of Gases Example 1: If CH4 and NH3 are both at 284 K, which gas has a greater speed? Step One: Add up the mass of each gas using the periodic table. Step Two: The lighter gas moves faster (think about a race between a 100-pound man and a 700-pound man, the lighter man would move faster) Example 2: Which gas has a faster speed between Br2 and CO2 if both are at 32°F?

MEASURING PRESSURE Manometers: Open Manometers: Closed Manometer: Measure pressure 2 kinds: open and closed Open Manometers: Compare gas pressure to air pressure Example: tire gauge Closed Manometer: Directly measure the pressure (no comparison) Example: barometer

KINETIC ENERGY AND TEMPERATURE Matter is made of particles in motion Particles have kinetic energy KE = (mv2)/2 OR KE = (ma)/2 Kinetic Energy is measured in Joules 1 J = 1kg•m2/s2 The mass must be in kg The velocity must be in m/s OR acceleration must be in m2/s2

KINETIC ENERGY AND TEMPERATURE Calculate the KE of a car with a mass of 1500 kg and a speed of 50 m/s Calculate the KE of a car with a mass of 6780 grams and a speed of 36 km/h

PHASE DIAGRAMS A diagram showing the conditions at which substance exists as a solid, liquid, or vapor Shows the temperature and pressure required for the 3 states of matter to exist Conditions of pressure and temperature at which two phases exist in equilibrium are indicated on a phase diagram by a line separating the phases Draw the phase diagram for water