2 Misconception about Matter Greeks, including Aristotle, did not believe that matter is made up of small particles called “atoms”.They believed that matter is “continuous” and has no space in it.Galileo and Newton believed otherwise.
3 Kinetic Molecular Theory Matter is mad up of small particles called “atoms”.Atoms are neither created, divided or destroyed during any type of chemical or physical change. [ Law of Conservation of Matter]
4 Atoms Elements molecules Compounds Every Element is made up of its own kind of atom. Different elements are made up of different atoms.Molecules are made up of elements.Molecule – is the simplest unit of a compound.
5 7 Diatomic ElementsCompounds – are pure substancesMixtures – combinations of diff. compounds
6 Phases of Matter Solid – have definite volume Liquid – have definite volume but no definite shapeGas – have no definite volume and no definite shapePlasma – have same property as gases but conduct electricity and interact strongly with magnetic fields
7 Effects of Temperature Converts compounds from one phase to anotherThermometerFahrenheit Celcius Kelvin conversionAbsolute zero = oC = lowest temperature possible = molecules do not move at all
8 HeatIs the measure of the internal energy that has been absorbed or transferred from one body to anotherInternal Energy – is the total kinetic and potential E of molecules of an objectExternal Energy – is the total kinetic and potential E of everyday-sized objects
9 Units of Heatcalorie – the amount of E needed to raise the temp. of 1 gram of substance 1 oC.Kilocalorie - the amount of E needed to raise the temp. of 1 kilogram of substance 1 oC.BTU – (British Thermal Unit) - the amount of E needed to raise the temp. of 1 lb. of substance 1 oF.
10 Law of Conservation of Energy When an object gives off energy, something must absorb it.Heat = qGiving off heat = -qAbsorbing heat = + qNote: +q = -q
11 Specific HeatSpecific Heat (C) - the amount of heat needed to raise the temp. of 1 gram of substance 1 oC.Compounds or Elements with high specific heat take awhile to heat up, but also take awhile to cool down.Heat = mass of compound x C x change in Tempq = mCDT
12 Ways for Heat to Flow1. Conduction – transfer of E from molecule o molecule- transfer of E from higher Temp. to lower Temp- happens primarily in solids
13 2. Convection – transfer of heat by large-scale displacement of molecules with high KE - Increased KE is transferred from molecule to molecule- happens primarily in liquids and gases- warm air is pushed to the top by cooler, more dense air and keeps being displaced by newly warmed air. As air cools, it sinks to the bottom.
14 3. Radiation – heat transfer due to temperature difference. - involves radiant E, which is the E that moves through space (includes visible light which is given off when objects are heated at a certain temperature)
15 Net Transfer of E when Temperatures are Different All objects above Absolute Zero absorb and emit radiant E.A hot object emits radiant E more than it absorbs radiant E.A cold object absorbs more radiant E than it emits radiant E.
16 Different Phase Changes Need HeatingSublimation: solid gas.Vaporization: liquid gas.Melting or fusion: solid liquid.Need CoolingDeposition: gas solid.Condensation: gas liquid.Freezing: liquid solid.
17 3 Laws of Thermodynamics 1st Law – Law of Conservation of Energy2nd law – The entropy of disorder of the universe is always increasing.3rd law – The entropy or disorder of a crystal at Zero Kelvin is zero. (Atoms do not move at absolute zero!)
18 Forms of EnergyElectromagnetic radiation wavelength, frequency and speedLightHeat
19 Electromagnetic Spectrum Radio WavesMicrowaves, Radar RaysInfraredVisibleUVX-raysGamma Rays