1. Temperature

2. Microscopic Atoms  Solid Atoms vibrate in a nearly fixed positionAtoms vibrate in a nearly fixed position  Gas Atoms apart, freely moving in the volume  Liquid Atoms close, but free to move aroundAtoms close, but free to move around  Atoms in matter are in constant motion.  Interaction of atoms determines the state of matter.

3. Macroscopic Properties  There are about 5 x 10 24 atoms in a golf ball.  We track its motion as a whole, not as atoms.  Density and pressure apply to the whole object, not the atoms.  These are macroscopic properties. Microscopic properties: mass, position, velocity, energy Macroscopic properties: mass, position, velocity, energy and density, pressure, temperature

4. Hot and Cold  Temperature is a macroscopic property of matter. Based on statisticsBased on statistics Doesn’t generally apply to single atomsDoesn’t generally apply to single atoms  Hot matter has more energy per atom on average than cold matter. Single atoms may have less energy in a hot itemSingle atoms may have less energy in a hot item

5. Thermal Contact  Two cups of water are in contact. Heat one cup Compare macroscopic properties  If they are the same they are in thermal contact. eg. metal cups  If different they are insulated. heater

6. Thermal Equilibrium  Two systems have the same temperature if they are in thermal equilibrium. Equilibrium between systemsEquilibrium between systems Measure of macroscopic propertiesMeasure of macroscopic properties  If two systems are not in thermodynamic equilibrium, they are not in thermal contact.

7. Law Zero  If two systems are each in thermodynamic equilibrium with a third system, then they are in thermodynamic equilibrium with each other.  This is the Zeroth Law of Thermodynamics. ABC A is in thermal equilibrium with B. C is in thermal equilibrium with B. Therefore, A is in thermal equilibrium with C.

8. Gas Thermometer  A system with known macroscopic properties may be placed in thermodynamic equilibrium.  A device that uses this is a thermometer. This thermometer uses the pressure of gas in a bulb. The meter measures the height in a manometer or barometer.

9. Kelvin  Temperature requires a scale to compare different systems.  The Kelvin (K) is the SI unit of temperature. Based on behavior of waterBased on behavior of water Linear pressure scaleLinear pressure scale Not degrees KelvinNot degrees Kelvin 10 -4 KSuperfluid liquid helium 4 KHelium boils 77 KAir boils 273 KWater melts 373 KWater boils 630 KMercury boils 1000 KCopper melts 6000 KSurface of the sun 10 6 KSolar corona 10 8 KHydrogen bomb

10. Temperature Scales  For everyday temperatures the Celsius scale (  C) is used.  Each  C is the same magnitude as 1 K. The zero is differentThe zero is different 0  C = 273.15 K0  C = 273.15 K Not quite T at P 3Not quite T at P 3  The English system uses the Fahrenheit scale (  F).  Ice point at 1 atm is 32 .  Boiling point at 1 atm is 212 .  Each  F is 5/9 of a  C.

11. Body Temperature  Normal body temperature is 98.6  F. What is the equivalent in  C and K?  If your fever is 101.6  F, by how much has it risen in  C and K?  The general formula applies for a conversion between scales. T C = (5/9)(T F – 32) (5/9)(98.6 – 32.0) = 37.0  C T = T C + 273.15 = 310.2 K  The difference use the fractional change.  T C = (5/9)  T F (5/9)(101.6 – 98.6) = 1.7  C  T =  T C = 1.7 K next