Matter & Change An Overview of Modern Chemistry!.
Post on 19-Dec-2015
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Chemistry is…• The study of the composition (not compost!),
structure, and properties of matter and the changes it undergoes
• Answers ?s-What is that material made of?• What is its makeup & internal arrangement• How does it behave when heated? Cooled?• Why does this material behave as it does?
6 Branches of Chemistry1. Organic Chemistry- the study of carbon
containing compounds
2. Inorganic Chemistry- the study of all substances not classified as organic, compounds without carbon- ex. Br
3. Physical Chemistry- the study of the properties and changes of matter and their relation to energy
4. Analytical Chemistry- The identification of the components and composition of materials
5. Biochemistry- The study of substances and processes occurring in living things
6. Theoretical Chemistry- The use of math and computers to understand and predict chemical behaviors
Types of Research
Basic ResearchRoy Plunkett- discovering Teflon
Applied ResearchReducing ozone brings about new refrigerants
Technological Development
1960 Business Computer
Historical Perspective of ChemistryAristotle- made observations of the natural world
Believed that the world was made of what 4 elements?
“Earth, Wind & Fire” & water
Alchemy- The attempt to turn metals into gold for wealth dominated “science” for 1,500 yrs.
Charles Lavoisier- observed & tested the natural world; the “Father of Chemistry”
Matter & It’s Properties
• Mass- is a measure of the amount of matter• Matter-anything that has mass & takes up
space• Is air matter? Name things that aren’t matter.
Yes!
Matter make-up
• Atom- smallest unit of an element that maintains the properties of that element
• Element- a pure substance made of only one kind of atom
• Compound- substance that is made from the atoms of 2 or more elements chemically bonded.
Properties of amount
Extensive Properties• Depend on the amount of
matter that is present• Ex. Volume– Mass– Amount of energy in a
substance
Intensive Properties• Properties that do not
depend on the amount of matter present
• Ex. Melting point– Boiling point– Density– Ability to conduct
electricity– Ability to conduct heat
Physical Characteristics
Properties• Physical Property:
characteristic that can be observed or measured without changing the identity of the substance
• Ex. Melting point, boiling point, color, weight, odor
Changes• Physical Change:• A change in a substance
that does not involve a change in the identity of the substance
• Ex. Grinding, cutting, melting, and boiling a material, change of state
Changes of State
Red Cube- solid (art in NYC)Solid Matter: State that has definite volume and definite shape
Diet Coke- liquidLiquid Matter: State that has definite volume and indefinite shape
Changes of State
Plasma is found in a fluorescent bulbPlasma Matter: high temperature physical state of matter in which atoms lose their electrons
Smoke bomb!Gas Matter: physical state that does not have definite volume or definite shape
Chemical Characteristics
Properties• Chemical Property-relates
to a substance’s ability to undergo changes that transform it into different substances
• Ex. Charcoal (Carbon) to burn to become CO2;
• Iron (Fe) to rust with O2
• Silver (Ag) to tarnish with• Sulfur (S) present
Changes• Chemical Change- A change in
which one or more substances are converted into different substances
• Ex. C + O2 -> CO2
• Reactant+Reactant ->Product
Means “yield” Decomposition is the
breakdown of a substanceHg(II)O2 Hg+2 + O2
Chemical Reactions
Composition
3 CO2 + 3 H2O C3H6O 3+ 3 O2
Making glucose
Decomposition
Hg(II) O Hg+2 + O2
Energy in relation to matter• Chemical changes often require the
absorption of heat energy and release of energy
• Think of a fire in the fireplace• Chemical changes often release light energy• Think of burning a candle• Energy can be absorbed or released but is not
destroyed.• Think of the law of conservation of energy
Classification of Matter
• Matter• Mixture Pure Substance(blend of 2 or more kinds (fixed composition with Matter retaining its own same characteristics & Identity & properties) composition; same ratio)
• Homogeneous Compounds• Air, sugar dissolved in water water, NaCl (salt)
• Heterogeneous Elements• Granite, wood, blood gold (Au), Silver (Ag)
Mixture vs. Pure Substances
1. Air?2. Purified
water?3. Handful of
pennies & dimes?
4. Copper wire?5. Oil and
vinegar salad dressing?
6. Gold ore?
Gas, mixture , homogeneous
Liquid, pure substance, compound, homogeneous
Solid, mixture, heterogeneous
Solid, pure substance, element
Liquid, mixture, heterogeneous
Solid, mixture, heterogeneous
Hetero or Homo?
Some mixtures are uniform in composition (while retaining its own identity and properties). These homogeneous mixtures are also called solutions. Example: saltwater
Heterogeneous mixtures are not uniform throughout- mixture of clay and water
The Organization of Elements- The Periodic Table
Periods-------------------------------------------------
GroupsOr
Families^|||||||||
Elements
An element is a pure substance made of only one kind of atom.
Some elements were named in Latin. Below are some:Cu cuprumAu aurumFe ferrumPb plumbum
Can you give the English name for them?
What about Sb?Na?K?Ag?
80
Hg200.59
Main Element Groups
• Metals• An element that is a good
conductor of heat and electricity.
• Characteristics:• Solid at room temp.• Malleability• Ductile• Tensile Strength• Most are silvery/grayish
luster
• Non metals• An element that is a
poor conductor of heat and electricity
• Characteristics:• Often gas at room temp• Ex. N, O, F, Cl• Solids tend to be brittle• Not malleable • Fewer in number
2 Exceptional Elemental GroupsMetalloids: An element that has some characteristics of metals and some characteristics of nonmetals.Metalloids make excellent semi-conductors found in computers, calculators, digital watches, televisions & radios
Noble Gases: Found as recently as 1962. Low reactivity characterize this group. Also known as Inert Gases. Name them:What can you assume about He from observing it’s use in balloons?
He, Ne, Ar, Kr, Xe, Rn, Uuo; He gas must be lighter than air
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