Heat and temperature

Heat and temperature

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  HEAT ANDHEAT AND TEMPERATURETEMPERATURE Autora:Marta García T.Autora: Marta García T.
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  WHAT IS HEAT?WHATIS HEAT?  HeatHeat is thermal energy transferred from ais thermal energy transferred from a warmer body or system, to a colder one. So,warmer body or system, to a colder one. So, one system releases heat and the other oneone system releases heat and the other one absorbs it.absorbs it.  This thermal transfer will stop when bothThis thermal transfer will stop when both systems have the same temperature (systems have the same temperature (thermalthermal equilibriumequilibrium).). http://www.quimicaweb.net/grupo_trabajo_ccnn_2/tema3/index.htm Autora: Marta García T.Autora: Marta García T.
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  Just to thinka bit….Just to think a bit…. a)a) Is it correct to say that hot objects emit heatIs it correct to say that hot objects emit heat and cold objects emit cold?and cold objects emit cold? b)b) Is it true that a blanket give us heat?Is it true that a blanket give us heat? c)c) What direction does heat flow in?:What direction does heat flow in?: Autora: Marta García T.Autora: Marta García T.
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   There aretwo units of measure for heat:There are two units of measure for heat:  JoulesJoules (J)(J)  CaloriesCalories (cal)(cal)  1J = 0,24 cal1J = 0,24 cal Autora: Marta García T.Autora: Marta García T.
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  WHAT IS TEMPERATURE?WHATIS TEMPERATURE?  TemperatureTemperature is the amount of heat in a bodyis the amount of heat in a body or system.or system. • The instrument which measuresThe instrument which measures temperature is thetemperature is the thermometerthermometer.. Autora: Marta García T.Autora: Marta García T.
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   There arethree scales to measure temperature:There are three scales to measure temperature:  Celsius ScaleCelsius Scale: is the most common scale. It is: is the most common scale. It is divided into a hundred parts, from the freezing pointdivided into a hundred parts, from the freezing point of water (0 ºC) to the boiling point (100 ºC).of water (0 ºC) to the boiling point (100 ºC).  Fahrenheit ScaleFahrenheit Scale: used in English-speaking: used in English-speaking countries. The freezing point of water is 32 ºF, andcountries. The freezing point of water is 32 ºF, and the boiling point is 212 ºF.the boiling point is 212 ºF.  Kelvin ScaleKelvin Scale: used by scientists. The freezing point: used by scientists. The freezing point of water is 273 K, and the boiling point is 373 K.of water is 273 K, and the boiling point is 373 K. Autora: Marta García T.Autora: Marta García T.
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  Autora: Marta GarcíaT.Autora: Marta García T.
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  HOW DOES HEATHOWDOES HEAT TRANSFER?TRANSFER?  There are three ways for heat to beThere are three ways for heat to be transferred, depending on the material:transferred, depending on the material:  ConductionConduction: this process occurs in most solids.: this process occurs in most solids. Heat is transferred by direct contact.Heat is transferred by direct contact. Autora: Marta García T.Autora: Marta García T.
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   ConvectionConvection: occursin liquids and gasses. Heat: occurs in liquids and gasses. Heat is transferred by the movement of currents.is transferred by the movement of currents. Autora: Marta García T.Autora: Marta García T.
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   RadiationRadiation: isthe transfer of heat by: is the transfer of heat by electromagnetic waves. Contact between theelectromagnetic waves. Contact between the source and the heated substance is notsource and the heated substance is not necessary, so is the way heat transfers in thenecessary, so is the way heat transfers in the universe (where there is no matter).universe (where there is no matter). Autora: Marta García T.Autora: Marta García T.
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  Label this pictureLabelthis picture about heat transfer:about heat transfer: http://www.profes.net/varios/videos_interactivos/definitivo.swf Autora: Marta García T.Autora: Marta García T.
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  WHAT ARE THEEFFECTS OFWHAT ARE THE EFFECTS OF HEAT?HEAT? 1)1) Changes of States:Changes of States:  EndothermicEndothermic: changes produced by heat: changes produced by heat absorption: melting, evaporation andabsorption: melting, evaporation and sublimation.sublimation.  ExothermicExothermic: changes produced by heat loss:: changes produced by heat loss: solidification, condensation and regressivesolidification, condensation and regressive sublimation.sublimation. Autora: Marta García T.Autora: Marta García T.
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  Do you remembertheDo you remember the names for the changesnames for the changes of state?of state? Autora: Marta García T.Autora: Marta García T.
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  2)2) ExpansionExpansion: itis the increase in volume which: it is the increase in volume which occurs when a system gains heat. Particlesoccurs when a system gains heat. Particles move faster, so they occupy more space.move faster, so they occupy more space. 3)3) ContractionContraction: it is the decrease in volume which: it is the decrease in volume which occurs when a system cools. Particles moveoccurs when a system cools. Particles move more slowly, so they occupy less space.more slowly, so they occupy less space. http://www.educared.net/aprende/anavegar 3/premiados/ganadores/c/651/Calor/index. htm Autora: Marta García T.Autora: Marta García T.