Chapter 5

• Every material is either a solid, liquid, or a gas
• Kinetic theory is used to explain how the states of matter behave
• Solids have fixed shape and volume
• Strong forces of attraction are called bonds
• Liquid has fixed volume but no fixed shape
• The particles attract eachother strongly when close, but the attractions weaken if they move apart
• Gas has no fixed shape or volume
• Gas particles move at fast speed are well spaced out
• Liquid particles are close together and attract each other, but the vibrations are too vigorous to stay in a single shape
• Solid particles are held together by strong forces of attraction (bonds) between the particles.
• When an object is heated it expands as its atoms gain energy from heat and start moving faster.
• An atom is the smallest possible amount of an element
• a group of atoms are called molecules
• Brownian motion is the random movement of particles in a liquid or gas.
• Kinetic energy is energy because of motion
• Potential energy is energy stored because of position
• Kelvin and celsius both have the same size
• The SI unit for temperature is kelvins (K)
• absolute zero is the lowest temperature possible, -273 degrees celsius
• the total kinetic and potential energy in a material is called internal energy
• the term thermal energy is used both internal energy and heat
• if hot material has contact with cold one, the hot one cools down and the cold one heats up (gaining internal energy)

  the energy transferred is called heat
• a temperature scale is a range of numbers measuring the level of hotness
• temperatures are usually measured with celsius (C) or called the centigrade scale
• pure water melts at 0 degrees celsius and boils at 100 degrees celsius
• temperature is measured using a thermometer
• thermometers can be made from mercury, alcohol, or gas
• alcohol thermometers use ethanol instead of mercury
• mercury thermometers have a glass tube filled with mercury that expands when heated
• the thermistor is a device that becomes a better electrical conductor when the temperature rises. Higher current flows from the battery, causing higher readings on the meter.
• thermocouple thermometer is made when two different metals are joined together and the temperature difference between them is measured. the greater the temperature difference, the greater the current
• higher the temperature, the greater the average kinetic energy per particle
• temperature isnt the same as heat
• in scientific work, temperature is measured with the Kelvin scale (K)
• Kelvin temperature = Celsius temperature + 273
• when greater accuracy is needed, absolute zero is -273.15 C
• when something is heated, the volume will increase, this is called thermal expansion
• momentum (P) = product of mass x velocity (m x v)
• at a constant volume, pressure increasues and temperature increases. pressure is proportional to temperature
• at constant pressure, volume increases and temperature increases, volume is proportional to temperature