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ChemistryThe study of matter and how it
changesMatter = has mass and takes up
spaceSimplest form of matter = AtomsDifferent types of atoms =
elements. (they cannot be broken down)
CompoundsAtoms of more than one
element bound together. Ex: H2O, C6H12O6, NaCl, HCl
Molecule = smallest unit that exhibits all the properties of that substanceEx: H2O, C6H12O6
Chemical FormulasChem symbols and numbers tell
us how many of each element is in a compound
Example: The chem formula for table sugar is C12H22O11. Each molecule contains 12 carbon atoms, 22 hydrogen atoms, and 11 oxygen atoms.
Types of Matter
Pure Substance = matter with fixed composition and definite properties
Mixture = Combination of more than one pure substance.
Ex: Grape Juice is a mixture of pure substances such as water, sugar, vitamins, etc…
Types of Pure Substances
Elements – listed on the Periodic Table
Compounds – Combination of elements
Types of MixturesHeterogeneous – subs are NOT
uniformly mixedExample: mixture of flour and water
Homogeneous – subs are evenly mixed (looks the same throughout) AKA Solution
Example: mixture of salt and water – the salt dissolves in the water
Liquid Mixtures Miscible – liquids are able to dissolve
into each other Homogeneous mixture of liquidsGasoline = homo. mixture of 100
compounds
Immiscible – liquids are NOT able to dissolve into one anotherHeterogeneous mixture of liquidsOil and water will not mix
BuoyancyThe force with which a more
dense fluid pushes a less dense subs up.
Ice is less dense than water.
Archimedes’ Principlethe buoyant force on an object equals
the weight of the fluid displaced by the object
Bernoulli’s PrincipleAs the velocity of a fluid
increases, the pressure exerted by the fluid decreases
Explains why planes can fly
Mixtures with GasesMany gases form mixtures
with other gases or liquidsEx: Air – homo. mixture of gases
Ex: Soda – homo. mixture of gas and liquid
Ex: Foam – mixture of gas and liquid
Kinetic TheoryAll matter is made up of atoms or
molecules.
The atoms/molecules are always in motion.
More massive atoms/molecules move slower.
States of MatterSolid LiquidGasPlasma – most common state in
the universeVery fast moving charged particlesMakes up stars
SolidsDefinite volume and shape –
“Rigid”
Atoms are held together with strong forces
Particles vibrate in fixed position
LiquidsDefinite volume, indefinite shape
Atoms slide past one another
Viscosity = property that describes the resistance of a fluid to flow
EnergyAbility to cause changes in the
states of matter (phase changes)
Evaporation Liquid GasEnergy is absorbed (by a liquid causing
atoms to move faster until they break away from the liquid surface to form a gas.)
More Phase ChangesCondensation
Gas LiquidReleases energy (energy is given from
the gas to the surroundings)
SublimationSolid GasEnergy is absorbedEx: CO2 (s) CO2 (g) Dry Ice
Phase Change Diagrams
Show the changes of state for any subs.
Show the temperatures where the phase change occurs
Is more energy used to convert ice to water or water to steam?
Heat of FusionAmount of heat required to
melt a solid at its melting point
Different for every subs.
Heat of VaporizationAmount of heat needed to
change a liquid into a gas at its boiling point
Also different for every subs.
State ChangesNo change in the composition or
mass of the atoms.Law of Conservation of Energy
Energy cannot be created or destroyed
Law of Conservation of MassMass cannot be created or destroyed
Properties of GasesThermal Expansion = gas
molecules become farther apart as temp increases
Pressure = Force exerted per unit area of a surfaceUnit: atmospheres (atm)Pressure around us comes from air
molecules
Boyle’s Law Relates pressure (P) and volume (V)
As P increases, V decreases
P1V1 = P2V2
Inverse relationship
Charles’s Law
Relates V and temperature (T)
As T increases, V increases
V1 = V2
T1 T2
Direct relationship
Chemical Properties Methods that a subs can use to
transform into a new subs with different properties
Reactivity = ability of one subs to combine with another subs
Ex: flammability, corrosiveness, rusting, explosiveness,
Physical PropertiesCharacteristic of a subs that can
be observed without changing the subs
Ex: Melting point (s l) Boiling point (l g)
Chemical ChangesChange that occurs to form a
new subs. (product has a different composition.)
Ex: Digesting food, steel rusting, food burning, gasoline combusting, milk souring
Signs a Chemical Change Occurred
OdorColor changeGas produced (bubbles)Solid producedTemperature change (hot or cold)