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Matter & Change. An Overview of Modern Chemistry!. 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
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Matter & Change An Overview of Modern Chemistry!
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?
Instruments refine our ability to measure- sight, weight, length
6 Branches of Chemistry 1. 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 Research Roy Plunkett- discovering Teflon Applied Research Reducing ozone brings about new refrigerants Technological Development 1960 Business Computer
Historical Perspective of Chemistry Aristotle- 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”
Alchemy -> Transmutation Ex. Of decay : Uranium -> Thorium -> Radium -> Radon -> Lead (not gold!)
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.
Matter! One atom elemental gold (Au) Compound -computer generated
Properties of amount Extensive Properties 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 • Depend on the amount of matter that is present • Ex. Volume • Mass • Amount of energy in a substance
Physical Characteristics Properties 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 • 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 of State Red Cube- solid (art in NYC) Solid Matter: State that has definite volume and definite shape Diet Coke- liquid Liquid Matter: State that has definite volume and indefinite shape
Changes of State Plasma is found in a fluorescent bulb Plasma 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 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 substance Hg(II)O2 Hg+2 + O2 • 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
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 Air? Purified water? Handful of pennies & dimes? Copper wire? Oil and vinegar salad dressing? 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 Groups Or Families ^ | | | | | | | | | Periods-------------------------------------------------
Elements An element is a pure substance made of only one kind of atom. Some elements were named in Latin. Below are some: Cu cuprum Au aurum Fe ferrum Pbplumbum Can you give the English name for them? What about Sb? Na? K? Ag? 80 Hg 200.59
Metals Non metals Main Element Groups 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 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 Groups Metalloids: 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