chapter 10 section 1 temperature. what is temperature? a measure of the average kinetic energy of...
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Chapter 10 Section 1
Temperature
What is Temperature?• A measure of the average kinetic
energy of the particles in an object– The faster the particles move, the more
kinetic energy– The more kinetic energy, the higher the
temperature
Tool: thermometerworks by thermal expansion
Thermal expansion- the increase in volume of a substance due to an increase in temperature
Substance gets hotter particles move faster particles spread out
therefore substance expands
Measuring temperature
Temperature Scales• Official SI scale- Kelvin scale
– Lowest temperature is absolute zero– Never been achieved– Absolute zero is the point when all
particle movement stops– Unit is kelvin
• Fahrenheit– Not widely used in science– Units °F
• Celsius– Divided in 100 equal parts– Units~°C
Temperature conversionTo Convert: Use this equation:
Celsius to Fahrenheit °C °F
°F = (9/5 x °C) +32
Fahrenheit to Celsius °F °C
°C = 5/9 x(°F - 32)
Celsius to Kelvin °C K
K = °C + 273
Kelvin to Celsius K °C
°C = K - 273
What is Heat?Chapter 10 Section 2
Heat is a Transfer of Energy
Heat ~ the transfer of energy between objects that are a different temperature
Energy is transferred from the object with the higher temperature to the object with the lower temperature
Thermal energy ~ the total kinetic energy of the particles that make up a substancedepends on amount and temperature of the substance
Thermal equilibrium~ when both objects reach the same temperature
Conduction, Convection, Radiation• Conduction ~ the transfer of thermal
energy from one object to another through direct contact– Conductors transfer thermal energy well
• Many metals– Insulators do not transfer thermal
energy well• wood
Conduction, Convection, Radiation• Convection ~ transfer of thermal
energy by the movement of a liquid or gas
• Convection current~ circular motion of liquids and gases due to density differences
Conduction, Convection, Radiation• Radiation ~ the transfer of energy
through matter or space as electromagnetic waves– Visible light, infrared waves
The Differences Between Temperature, Thermal Energy, and Heat
Temperature Thermal Energy Heat
A measure of the average kinetic energy of the particles in a substance
The total kinetic energy of the particles in a substance
The transfer of energy between objects that are at different temperatures
Expressed in degrees Fahrenheit, degrees Celsius, or kelvins
Expressed in joules Amount of energy transferred expressed in joules or calories
Does not vary with the mass of a substance
Varies with the mass and temperature of a substance
Varies with the mass, specific heat capacity, and temperature change of a substance