 Matter takes up space and has mass  Matter is made of atoms, usually chemically bonded into molecules  Exists in different states

 There are 4 states of matter: solid, liquid, gas, and plasma  State of a sample of matter depends on the kinetic energy of the molecules or atoms in the sample  Kinetic energy is the energy of moving things

 Kinetic energy moves from areas of higher energy to areas of lower energy  High energylow energy  High energy low energy  Kinetic energy is measured in Joules (J)

 Solids have a definite shape and a definite volume  The atoms and molecules that make a solid, vibrate in place but do not move around

 Particles in solid matter are held close together by forces between them  Particles vibrate but don’t have enough energy to move out of position

 Liquids have a fixed volume, but take the shape of the container in which they are found  The atoms and molecules that make a liquid can flow around each other

 Particles in liquid matter are held close together by forces between them  Particles are close enough so that liquid matter has a definite volume  Particles have enough energy to move over and around each other

 Gases have neither a definite shape nor volume  They take the shape of their container

 Particles of a gas have enough energy to separate completely from one another  Particles of a gas are not close together so they can be squeezed into a smaller space  Particles have enough energy to move in all directions until they have spread evenly throughout their container

 Plasma is a gaslike mixture of positively and negatively charged particles  They have so much energy that they collide violently and break apart into charged particles  Found in lightning bolts, neon signs, Northern lights, and stars

 It is made of electrons and positive ions that have been knocked apart by collisions at very high temperatures or in situations where the matter has absorbed energy  Least common state of matter on Earth but is the most common state of matter in the universe, because stars are made of matter in the plasma state

 Almost all matter expands when it gets hotter and contracts when it cools  When matter is heated the particles move faster, vibrate against each other with more force  Particles spread apart slightly in all directions and the matter expands

 This effect happens in solids, liquids, and gases  Examples are the liquid in a thermometer and expansion joints in roads and buildings

 When matter gains or loses energy, it can change from one state to another  Different states of matter correspond to different amounts of energy, these amounts are specific to particular kinds of matter  Temperature can be used to measure the amounts of energy present in the matter

 Boiling: liquid changes to a gas  Freezing: liquid changes to a solid  Condensing: gas changes to a liquid  Melting: solid changes to a liquid  Evaporating: liquid changes to a gas (but a temperatures lower than the boiling point)  Subliming: solid changes into a gas without becoming liquid (opposite of sublimation is deposition)

 Boiling point: temperature at which a liquid becomes a gas, this temperature is an identifiable characteristic for different substances  Melting point: temperature at which a solid becomes a liquid

 Substances condense or boil at their boiling point, depending on whether energy is being added or taken away  Substances melt or freeze at their melting point, depending on whether energy is being added or taken away

 Transitions between solid, liquid, and gaseous phases typically involve large amounts of energy compared to the energy needed to change the temperature of a solid or liquid or gas.  It takes lots of energy to change states (temperature stays constant until state is completely changed).

 If heat were added at a constant rate to a mass of ice to take it through its phase changes from solid to liquid water and then to steam, the energies required to accomplish the phase changes would lead to plateaus in the temperature vs time graph.

 tions/projectfolder/flashfiles/propOfSoln/collig ative.html interactive boiling point and freezing point changes tions/projectfolder/flashfiles/propOfSoln/collig ative.html  Adding solute to water increases its boiling point, the solute interacts with the water and energy must be added to overcome the interactions so that the water can then change from a liquid to a gas

 tions/projectfolder/flashfiles/propOfSoln/collig ative.html interactive boiling point and freezing point changes tions/projectfolder/flashfiles/propOfSoln/collig ative.html  Adding solute to water decreases its freezing point, the solute interacts with the water and energy must be removed to overcome the interactions so that the water can then change from a liquid to a solid

 Thermal energy is the total energy of the particles in a material  Thermal energy includes the kinetic energy of the particles (their motion or vibration)  Thermal energy also includes the potential energy of the particles (energy due to forces acting within or between the particles)

 Heat is the name given to thermal energy that moves or is transferred  In many things that you read, heat and thermal energy are used interchangeably

 Heat moves from areas of greater heat (more thermal energy) to areas of lesser heat (less thermal energy)

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 Temperature is the measure of the average kinetic energy of the particles that make up a sample of matter.  As the particles move faster, the temperature rises  As the particles slow down, the temperature falls

 Law of Conservation of Energy – Energy is neither created nor destroyed. It can change forms.  Heat transfer follows the Law of Conservation of Energy  Energy transfers from areas of high energy to areas of low energy but can neither be created nor destroyed

 Liquid inside the thermometer is made of molecules  As kinetic energy of molecules increases, liquid molecules move faster and liquid expands  Liquid rises in the tube inside the thermometer

 Rising kinetic energy = rising liquid = rising temperature on thermometer scale  Heating and cooling a thermometer: media/chapter1/lesson3 media/chapter1/lesson3

 First scale developed  Water melts/freezes at 32 ° F and boils at 212 ° F  Salt water melts/freezes at 0 ° F, body temperature was 96 ° F and degrees were divided into 12s and then into 8s between these two points

 Celsius scale based on 100 degrees between freezing and melting of water  Water melts/freezes at 0 ° C and boils at 100 ° C

 Important scale used in most of science  Based on a single point ( absolute zero ) which is given a value of 0 degrees.  From there, the scale increases by degrees that are the same size as Celsius degrees.

 It is a scale that is based on energy content, rather than on arbitrary temperature values like the other two scales (based on water).  Water freezes at the value K and boils at Kelvin.

 0 on the Kelvin scale  Point at which all particle motion stops  Matter has no thermal energy at absolute zero

 Law of Conservation of Energy – Energy is neither created nor destroyed. It can change forms.  Heat transfer follows the Law of Conservation of Energy  Energy transfers from areas of high energy to areas of low energy but can neither be created nor destroyed

 Physical property of matter  Relates to a substance’s ability to absorb heat  Also called specific heat

 Specific heat capacity of a substance is the amount of energy (Joules) required to raise the temperature of 1 gram of the substance by 1 ° C Specific heat capacity =

 Objects with low specific heat capacities heat up more quickly than objects with high specific heat capacities.  It takes less energy to raise their temperatures  They also transfer their heat more quickly so they cool down faster

 Water has a fairly high specific heat capacity, J/g ° C  This means it takes a lot of energy to raise the temperature of water 1 ° C compared to the amount of energy it takes to heat something with a lower specific heat capacity  Example: Iron (0.45 J/g ° C) needs much less energy to change its temperature

 Objects with low specific heat capacities are better conductors of heat  Objects with high specific heat capacities are better insulators because they don’t heat up as quickly

 An insulated container that prevents a chemical reaction from gaining heat from its surroundings or losing heat to its surroundings

 Calorimeter experiments to calculate specific heat capacities of objects use the Law of Conservation of Energy and the known specific heat capacity of water  When a heated object is placed in a cup of cold water, the heat will move from the object to the water  When the temperature stops changing, the temperature of the object and water are now the same

 Energy transferred to the water is equal to the energy transferred from the object

Calculations: Known: Specific heat capacity of water = J/g ° C Energy transferred to water = mass of water (g) x Temp change ( ° C) x J/g ° C Specific heat capacity of object =

 p. 22 heating and cooling gas in a bottle  media/chapter1/lesson5 media/chapter1/lesson5  p. 24 heating and cooling a metal ball  media/chapter1/lesson4 media/chapter1/lesson4