Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Chapter 2

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Matter  Substance that occupies space  Substance that has mass  Mass—measure of the amount of atoms  All matter is made up of atoms  Possess unique physical and chemical properties

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Three subatomic particles:  Protons  Electrons  Neutrons  Protons and neutrons form the nucleus  Electrons revolve around the nucleus  Bohr model is the most popular model

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

 Protons—subatomic particle (+) charge  Electrons—subatomic particle (–) charge  Neutron—subatomic particle with no electrical charge  Atomic number helps to classify atoms  Atoms are also known as elements  Over 109 different atoms or elements

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Four states:  Solids– Liquids  Gases– Plasma  Atoms in solids are tightly packed  Atoms in solids are restricted in movement  Atoms are in a crystal pattern  Matter in solid state has a definite shape

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 Liquids are composed of atoms that are more loosely arranged  Atoms have more freedom of movement  Liquids have no definite shape  Atoms are arranged in long chains or clumps  Movement of atoms is less restrictive

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 When a solid turns into a liquid  Refers to change in state or phase change  Phase changes depend on certain temperature and pressure  Temperature of change:  from solid to liquid called melting point  from liquid to solid called freezing

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Atoms in a gas:  Highest degree of movement  Undergo constant collisions with other atoms  Gas has no definite shape  Collisions with walls of a solid container  Causes pressure  More collisions the higher the pressure

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 Liquid changes phase to a gas— vaporization  Temperature to change a liquid to a gas— boiling point  Change of a gas to a liquid—condensation  Solid directly into a gas—sublimation

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Plasma  Atoms of gas are exposed to high energy  Atoms begin to ionize and lose electrons  This creates a high-energy fluid gas mixture composed of ions and electrons  Stars are composed of plasma

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  109 different atoms make up Earth’s elements  Chemically joined atoms are called compounds  Compounds are referred to as molecules  More than 10 million compounds exist  Two substances mixed are called a mixture

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Relationship between matter and energy  Fundamental cause for existence  Albert Einstein  Energy and mass have a mutual relationship  E = mc 2  Ability to do work or cause change  Motion when matter is exposed to energy

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Two basic forms:  Kinetic  Energy of motion  Movement of Earth around the Sun  Potential  Stored energy  Gasoline in the tank of your car

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Energy cannot be created or destroyed  Energy only changes form  Energy changes from one form to another  No real gain or loss  Forms of energy:  mechanical – gravitational – radiant  thermal – electrical – magnetic  nuclear – chemical

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Kinetic energy of movement or vibration  Travels in the form of a wave  The higher the electromagnetic radiation, the shorter the wavelengths  The lower the electromagnetic radiation, the longer the wavelengths  Electromagnetic spectrum:  Energy and wavelength of different forms

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Gamma rays—highest energy waves  Wavelength 1 billionth of a centimeter  Radio waves—lowest energy waves  Wavelength as large as 10 kilometers  Electromagnetic waves travel at the speed of light:  186,000 miles per second

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Electromagnetic energy interacts with matter:  Refraction—waves change direction and bend  Reflection—waves bounce off substances  Scattering—waves refracted or reflected  Absorbed—wave’s energy is taken in  Transmission—waves pass through matter

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Three fundamental processes:  Conduction—transfer by direct contact  Radiation—movement in an empty space  Convection—circular movement of heat  In gas or liquid  Caused by differences in temperature & humidity

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Temperature—substance’s average kinetic energy  Higher temperature, more motion of atoms  Temperature measured on three scales:  Fahrenheit  Celsius  Kelvin

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Fahrenheit and Celsius  Freezing point—32°F and 0°C  Boiling point—212°F and 100°C  Kelvin—measures average kinetic energy  0°K—all particles stop motion  Temperature never reached on Earth  Based on absolute zero  0°K = °F and °C

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Heat—measure of flow of kinetic energy  Total kinetic energy in a system  Flows from high to low kinetic energy  Called a sink  Calorie = energy to raise 1 gram H 2 O 1°C  Specific heat  Heat to raise 1 gm of a substance 1°C  Also called heat capacity

Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.  Latent heat of condensation  Water vapor to a liquid  1 gram water vapor into liquid  840 calories released  Liquid water to a solid—80 calories released  Latent heat of vaporization  Liquid water vaporizes into water vapor  840 calories absorbed