CHAPTER 1 1.1 What is Chemistry? 1.2 Describing Matter 1.3 How is Matter Classified?
Chapter 1 Matter, Energy, & Change. 1.1 What is Chemistry? 1.1 What is Chemistry? the study of...
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Transcript of Chapter 1 Matter, Energy, & Change. 1.1 What is Chemistry? 1.1 What is Chemistry? the study of...
Chapter 1Chapter 1
Matter, Energy, & ChangeMatter, Energy, & Change
1.1 What is Chemistry?1.1 What is Chemistry?•the study of matter and its transformations
Why study chemistry?
•learn fundamental physical models •gain technical perspective on current events •develop problem solving skills •appreciate life's little mysteries •Most of the building materials, clothes, and medicines today are
the result of chemistry
Branches of ChemistryBranches of Chemistry
Organic- Organic-
Inorganic-Inorganic-
Physical-Physical-
Biochemistry-Biochemistry-
Analytical-Analytical-
the study of the structures, synthesis, and reactions of carbon- compound
the study of the properties and reactions of inorganic compounds
•dealing with the physical properties of chemical substances
•study of the chemistry of living things
analysis of material samples to gain an understanding of their chemical composition and structure.
1.2 Matter and Energy1.2 Matter and Energy Matter______________________________Matter______________________________
•Matter – anything that has mass and occupies space•Inertia – the tendency of a body to stay at rest or to continue to move at the
same velocity, unless acted on by an outside force. A tractor trailer
has more inertia than a bicycle. A bowling ball has more inertia than
a tennis ball.
Mass and weight – used interchangeably, but there is a difference…
Mass -a quantity of matter, mass is measured using a balance
Weight-a measure of gravity's effect on something; use a scale to measure weight
Law of Conservation of Mass -Matter can neither be created nor destroyed in chemical or physical changes.
Example – sodium metal + chlorine gas ---> table salt, an edible crystal
_____Energy_________________________Everything that you see or sense is either matter or the interactions of energy and matter. True or False? Example: a book – a chunk of matter – hold it up – potential energy – drop it – kinetic energy
Energy – the ability to cause change or the ability to do work. (two types)
Kinetic –
Potential -
the energy of motionEx. baseball in flight, car rolling down a street
stored energy waiting to be releasedEx: gasoline, water behind a dam
Law of Conservation of EnergyLaw of Conservation of Energy Energy can change forms, but it cannot be created or destroyed by ordinary
chemical or physical changes
Gas Liquid Solid
•low density •easy to expand/compress •shape - fills container •quick diffusion•volume – container
•high density •hard to expand/compress •takes shape of container •middle diffusion•definite volume
•high density •hard to expand/compress •rigid shape •low diffusion•definite volume
1.3 States of Matter1.3 States of Matter
Plasma – A highly ionized gas. The fourth state of matter (it does matter). 99% of all matter in the universe is in a plasma state. Lightning, neon lights and fire are natural examples of plasma on Earth. Plasma tv’s? What are they all about?Plasma in flat-panel display technology that ignites small pockets of gas to light phosphors. Each plasma panel contains thousands of tiny tubes filled with ionized gas that, when excited by electricity, glow in different colors and intensities to create an image.
Properties and Changes of Matter
Properties – characteristics that enable us to distinguish one kind of matter from another
describe materials by listing their properties
Chemical properties vs. physical properties Measurement of a Ex: determining the flammability of gasoline involves burning it, producing
CO2 and H2O; wood burning, rusting iron, tarnishing silver, leaves changing colors, baking a cake
Measurement of a
Ex: density, color, boiling point, volume, temperature, and mass.
chemical property involves a chemical change.
physical property may change the arrangement but not the structure of the molecules of a material.
Intensive properties vs. Intensive properties vs. extensive propertiesextensive properties
•Extensive properties change when sample size changes; intensive properties don't.
Mass of WaterMass of Water 100.0 g100.0 g 10.0 g10.0 g
Volume of WaterVolume of Water 0.100 L0.100 L 0.010 L0.010 L
Temperature of WaterTemperature of Water 25 C25 C 25 C25 C
Density of WaterDensity of Water 1.00 g/ml1.00 g/ml 1.00g/ml1.00g/ml
Chemical Change vs. Physical Change
•A chemical change occurs when
Ex. chemical change: sodium metal + chlorine nonmetal --> table salt (crystal, white, edible) Ex. physical change: cutting paper, chopping wood, freezing water
Signs of a chemical change
a substance is converted into a different substance
• evolution of heat and light•production of a gas
• formation of a precipitate
Energy and Changes in Matter - Energy and Changes in Matter - Chemical reactions involve energyChemical reactions involve energy
ExothermicExothermic
releases energyreleases energy
reactants --> products + heatreactants --> products + heat
water(l) → ice(s) + heatwater(l) → ice(s) + heat
Graph:Graph:
EndothermicEndothermic
absorbs energyabsorbs energy
reactants + heat ---> productsreactants + heat ---> products
ice(s) + heat → wate(l)ice(s) + heat → wate(l)
Graph:Graph:
Water (reactants)
Ice (products)
Energy
heat
ice (reactants)
Water (products)
Energyheat
Examples of Exothermic Examples of Exothermic ProcessesProcesses
making ice cubesmaking ice cubes formation of snow in clouds formation of snow in clouds condensation of rain from water condensation of rain from water vaporvapor a candle flame a candle flame mixing sodium sulfite and mixing sodium sulfite and bleach bleach rusting iron rusting iron burning sugar burning sugar forming ion pairsforming ion pairs combining atoms to make a gas combining atoms to make a gas
moleculemolecule mixing strong acids and watermixing strong acids and waternuclear fissionnuclear fission
Examples of Endothermic Examples of Endothermic ProcessesProcesses
melting ice cubesmelting ice cubes conversion of frost to water conversion of frost to water vapor evaporation of watervapor evaporation of water forming a cation from an atom forming a cation from an atom in the gas phasein the gas phase baking breadbaking bread cooking an eggcooking an egg producing sugar by producing sugar by photosynthesisphotosynthesis separating ion pairsseparating ion pairs splitting a gas molecule apartsplitting a gas molecule apart mixing water and ammonium mixing water and ammonium nitrate melting solid saltsnitrate melting solid salts
1.4 Classification of Matter
Separate physically
Matter
MixturesPure
Substances
Heterogeneous Homogeneous
Suspension
Compounds Elements
Solution Colloid
Separate chemically
MixtureMixture
combination of two or more kinds of combination of two or more kinds of matter, but each retains its own matter, but each retains its own physical propertiesphysical properties
HeterogeneousHeterogeneous
composition is not uniform where composition is not uniform where samples are differentsamples are different
HomogeneousHomogeneous
Uniform composition; every sample is Uniform composition; every sample is the samethe same
SuspensionSuspension
Solid in liquidSolid in liquid
muddy water, granitemuddy water, granite
SolutionSolution
small particles that won’t scatter lightsmall particles that won’t scatter light
ex: air, salt waterex: air, salt water
ColloidColloid
particles larger than molecules, particles larger than molecules, scatterlightscatterlight
Shaving cream, starch waterShaving cream, starch water
Pure SubstancePure Substance
homogeneous sample of matter that homogeneous sample of matter that always has the same compositionalways has the same composition
CompoundCompound
substance that can be decomposed substance that can be decomposed into 2 or more substances by chemical into 2 or more substances by chemical changechange
Ex: NaCl, H2O, C6H12O6, CO2Ex: NaCl, H2O, C6H12O6, CO2
ElementElement
substance that cannot be broken down substance that cannot be broken down by ordinary chemical changeby ordinary chemical change
Ex: Au, Cu, Ni, NaEx: Au, Cu, Ni, Na
1.5 The chemical elements1.5 The chemical elementsThe periodic table compactly shows relationships between elements, and features are:
Periods are horizontal rows on the table. - Have the same number of electron shells
Groups (or families) are columns on the table. - Have similar chemical properties.
Blocks are regions on the periodic table
www.periodictable.com
Types of MetalsTypes of Metals Alkali MetalsAlkali Metals (Group IA, first column ) (Group IA, first column )
soft, extremely reactive metals soft, extremely reactive metals react with cold water to form hydrogen gas react with cold water to form hydrogen gas form +1 ions form +1 ions Li, Na, K, Rb, Cs, FrLi, Na, K, Rb, Cs, Fr
Lithium SodiumPotassium
Types of MetalsTypes of Metals alkaline earth metalsalkaline earth metals (Group IIA, (Group IIA,
second column): second column): soft, reactive metals soft, reactive metals compounds are a major component of compounds are a major component of
earth's crust earth's crust form +2 ions form +2 ions Be, Mg, Ca, Sr, Ba, RaBe, Mg, Ca, Sr, Ba, Ra
Magnesium Barium Beryllium
Types of MetalsTypes of Metals Transition Metals (columns 3-12)Transition Metals (columns 3-12)
hard, dense metals hard, dense metals less reactive than Group IA and IIA less reactive than Group IA and IIA
Nickel Gold Chromium
Types of MetalsTypes of Metals Rare earth metalsRare earth metals are the elements are the elements
at the bottom of the table. at the bottom of the table. lanthanides (top row) lanthanides (top row) actinides (bottom row) actinides (bottom row)
Lanthanide Uranium
NonmetalsNonmetals
halogenshalogens (Group VIIA, next-to-last column): (Group VIIA, next-to-last column): poisonous and extremely reactive nonmetals poisonous and extremely reactive nonmetals fluorine and chlorine are yellow-green gases fluorine and chlorine are yellow-green gases bromine is a volatile red-brown liquid bromine is a volatile red-brown liquid iodine is a volatile blue black solid iodine is a volatile blue black solid all form -1 ions all form -1 ions
noble gasesnoble gases (Group 0, last column) (Group 0, last column) all are all are monatomicmonatomic gases gases a. k. a. inert gases; almost completely unreactive a. k. a. inert gases; almost completely unreactive
Properties of Metals - MacroProperties of Metals - Macro
malleablemalleable: can be hammered into thin : can be hammered into thin sheets sheets
ductileductile: can be drawn into wire : can be drawn into wire
conduct heat and electricity well conduct heat and electricity well lustrouslustrous
Properties of Metals - MicroProperties of Metals - Micro Appear different colors when metals Appear different colors when metals
are in tiny clusters (nanoparticles)– are in tiny clusters (nanoparticles)– up to 30 atomsup to 30 atoms
Stained glassStained glass Lycurgus cupLycurgus cup
How Small is a How Small is a Nanoparticle?Nanoparticle?
NanoNano 1 billionth of a 1 billionth of a
metermeter
Properties of Nonmetals
• Not Malleable or ductile – brittle
• Poor conductors of electricity
• dull
Properties of Metalloids
• Properties of metals and nonmetals