ChemistryChemistry
Matter and Matter and ChangeChange
Chemistry is…
…the study of the composition, structure, and properties of matter and the changes it undergoes
C2H5OH + 3 O2 2 CO2 + 3 H2O + Energy
Reactants Products
MatteMatterr
Anything that has mass and occupies space
MasMasssA measure of the amount of matter
AtomAtomThe smallest unit of an element that maintainsthe properties of that elementElementElement
A pure substance made of only one kind of atom
CompouCompoundnd
A substance that is made from the atoms of two or more elements that are chemically bonded.
Sucrose – C12H22O11
Sucrose is also known as table sugar, and is used to make Gummy Bears!
Properties of Properties of MatterMatterExtensive propertiesExtensive properties
Intensive propertiesIntensive properties
Volume
MassEnergy Content (think Calories!)
depend on the amount of matter that is present.
do not depend on the amount of matter present.
Melting point
Boiling point
Density
Physical Physical ChangeChangeA change in a substance that does not involve a change in the identity of the substance.
Example:
Phase Changes
Phase Phase DifferencesDifferences
SolidSolid – definite volume and shape; particles packed in fixed positions.LiquidLiquid – definite volume but indefinite shape; particles close together but not in fixed positionsGasGas – neither definite volume nor definite shape; particles are at great distances from one anotherPlasma – high temperature, ionized phase of matter as found on the sun.
Three PhasesThree Phases
Copper Phases - SolidCopper Phases - Solid
Copper Phases - LiquidCopper Phases - Liquid
Copper Phases – Vapor (gas)Copper Phases – Vapor (gas)
Chemical Chemical ChangeChangeA change in which one or more substances are converted into different substances.
Heat and light are often evidence of a chemical change.
Classification of Matter
Separation of a MixtureSeparation of a Mixture
The constituents of the mixture retain The constituents of the mixture retain their identity and may be separated by their identity and may be separated by physical means.physical means.
Separation of a MixtureSeparation of a Mixture
The components of dyes such as ink may be separated by paper chromatography.
Separation of a MixtureSeparation of a Mixture
Distillation
Separation of a CompoundSeparation of a CompoundThe Electrolysis of water
Water Hydrogen + Oxygen
H2O H2 + O2
Reactant Products
Compounds must be separated by chemical means.
With the application of electricity, water can be separated into its elements
The Periodic TableThe Periodic Table
Period
Group or family
PeriodGroup or Family
Properties of MetalsProperties of Metals Metals are good conductors of heat and electricity
Metals are malleable
Metals are ductile
Metals have high tensile strength
Metals have luster
Examples of MetalsExamples of Metals
Potassium, K reacts with water and must be stored in kerosene
Zinc, Zn, is more stable than potassium
Copper, Cu, is a relatively soft metal, and a very good electrical conductor.
Mercury, Hg, is the only metal that exists as a liquid at room temperature
PropertiesProperties of Nonmetalsof Nonmetals
Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element. Nonmetals are poor conductors of heat and electricity Nonmetals tend to be brittle Many nonmetals are gases at room temperature
Examples of NonmetalsExamples of Nonmetals
Sulfur, S, was once known as “brimstone”
Microspheres of phosphorus, P, a reactive nonmetal
Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure
Properties of MetalloidsProperties of Metalloids
Metalloids straddle the border between metals and nonmetals on the periodic table.
They have properties of both metals and nonmetals.Metalloids are more brittle than metals, less brittle than most nonmetallic solids Metalloids are semiconductors of electricity Some metalloids possess metallic luster
Silicon, Si – A MetalloidSilicon, Si – A Metalloid
Silicon has metallic luster Silicon is brittle like a nonmetal Silicon is a semiconductor of electricity
Other metalloids include:
Boron, B Germanium, Ge Arsenic, As Antimony, Sb Tellurium, Te
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