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Chemistry intro
The document provides an overview of atomic structure and the periodic table. It defines atoms as the smallest unit of matter and describes their components of protons, neutrons, and electrons. Models of the atom including Thomson's plum pudding model, Rutherford's nuclear model, Bohr's shell model, and the cloud model are summarized. The periodic table is arranged based on atomic number and electrons in the outer shell. Elements are grouped based on similar properties, with metals on the left and nonmetals on the right.
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Chemistry intro
- 1. Chemistry INTRO Atoms &the Periodic Table Robin D. Seamon
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- 3. Matter is everythingaround you: Matter something that has mass & takes up space (volume) Mass number of atoms in it (kg) Volume the amount of space it takes up
- 4. Atoms: smallest unitor building block of matter 1. Atoms LINK Video (7 min) 2. NOVA Atoms Video (1 min) 3. Crash Course Chemistry: Atom (10 min) http://archive.stsci.edu/fus e/scisumm/sci_d2h.html http://www.eskom.co.za/nuclear_energy/fuel/fuel.html Molecule: two or more atoms bound together http://www.ces.fau.edu/
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- 6. Electron (-) nucleus Proton (+) Neutron 80 Hg 200.59 Mercury Atomicnumber (# of protons) Atomic weight (mass of protons & neutrons) symbol Element name VIDEO 1: Atoms: Space Between (1 min) VIDEO 2: Electrons, Protons, Neutrons ( 3 min) A T O M
- 7. Democritus (Greek) philosopherwho imagined cutting matter up until it could no longer be cut into smaller particles. He called this smallest unit atomos “can’t be split.” ATOMIC MODELS http://www.iep.utm.edu/democrit/ 460- 370 B.C.E. Joseph Thomson (British) 1897 discovered the electron -plum pudding model: electrons floated in the positive proton mass
- 8. Ernest Rutherford Model(British) (1909) • Described the nucleus • Said the atom was 99.9% empty space • Said nucleus was + • Said nucleus was 100,000 X smaller than the atom http://www.nobelprize.org/nobel_prizes/chemi stry/laureates/1908/rutherford-bio.html
- 9. Niels Bohr Model:(Danish) 1913 • ONION MODEL said rings are not actual orbits, but levels or SHELLS that represent the location of an electron wave. • Said electrons could jump between those shells releasing energy https://thespectrumofriemannium.wordpress.com/t ag/sommerfeld-corrections/ http://www.nndb.com/people/560/000024488/
- 10. VIDEO Crash CourseAtomic Model Theory (9 min) Erwin Schrodinger (Austrian) & Werner Heisenberg (German) 1925 -CLOUD MODEL • Probability Function: cloud-like region where electrons are likely to be found • *Can’t say with certainty where the electron is at any point in time, yet describes where it ought to be • ~think of it like an electron leaving a trace of where it was, the collection of these traces looks like a cloud • The probable location happens to coincide with locations specified by Bohr’s model! http://www.regentsprep.org/Regents/phy sics/phys05/catomodel/cloud.htm
- 11. Electron shell: setof allowed states that electrons can have around the nucleus Atoms fill their innermost shells before moving outward MAXIMUM CAPACITY: 1st Shell: up to 2 electrons 2nd Shell: up to 8 electrons 3rd Shell: up to 18 electrons 4th Shell: up to 32 electrons 2 2 8 2 8 2 8 18 18 32
- 12. SHELL NUMBER (n) ABSOLUTEMAX CAPACITY VALENCE CAPACITY 1 2 2 2 8 8 3 18 8 4 32 8 n 2n2 8 Valence electrons: electrons in the outermost energy level Octet Rule: the valence shell normally holds no more than 8 electrons, regardless of the capacity it would otherwise have. *atoms are most stable when they have full valence shells * This tendency is the driving force behind chemical reactions, (explains why elements combine the way they do) VALENCE SHELL: outermost shell
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- 15. Pure Substance: allof the particles are the same Element: all the atoms are the same Compound: elements are the same- in a repeating pattern
- 16. mixture Can be physically separated compound Chemically boundelement Chemically bound 16 element: lotsof the same atom compound: lots of the same molecule mixture
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- 18. Pure Substance Element Compound Mixture Homogeneous Mixture Heterogeneous Mixture Carbon C OxygenO Salt NaCl Sugar C H O Water H O2 2 2 12 22 11 Solution Alloy Saltwater NaCl + H O Brass Cu + Zn Bronze Cu + Sn Steel Fe + C Salad Conglomerate CLASSIFICATION OF MATTER 2
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- 20. LAB: Arrange theElements DIRECTIONS: 1. Think about properties you could use to group and arrange the element cards. 2. Arrange the elements in an order of your choosing. 3. Write the rules you used to organize. 4. Compare to Mendeleev’s table
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- 22. CONCLUSIONS: Dmitri Mendeleev (Russian)1869 • Saw pattern in elements regarding their chemical properties (density, appearance, melting point) • He arranged them in a pattern of increasing atomic mass Atomic mass: the mass of the protons + neutrons (electrons are too small to weigh) • He predicted missing elements based on the pattern • A few elements’ properties didn’t fit, but the math was right http://www.glogster.com/andythehandsome/dmitri-ivanovich- mendeleev/g-6mf34dudha5i9e4oi3ttea0
- 23. Henry Mosley (British)1914 determined the atomic number • Atomic number: number of protons in an atom • He slightly adjusted Mendeleev’s periodic table to be in order of atomic number. http://en.wikipedia.org/wiki/Henry_Moseley
- 24. Glenn T. Seaborg(American) 1951 discovered the • Actinid elements & they follow the law Periodic Law: repeating chemical & physical properties of elements change periodically with a pattern http://www.nobelprize.org/nobel_prizes/chemis try/laureates/1951/seaborg-bio.html Periodic Table Crash Course VIDEO ( 10 min)
- 25. 80 Hg 200.59 Mercury Atomic number (# ofprotons) Atomic weight (mass of protons & neutrons) symbol Element name How to Read the Periodic Table of Elements Elements VIDEO SONG (3 min)
- 26. 1 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Groups- Families Color of the symbol indicates whether the element is a solid, liquid, or gas at room temperature Periodic Table SONG LINK INTERACTIVE Periodic TABLE Metalloids are on the stair- step between metals & non- metals Elements 1-92 are found in Nature. The rest are man- made (synthetic) Periods
- 27. Elements 1-92 arefound in Nature. The rest are man-made. Some are yet to be created/discovered in the lab. Periods are read • The number of electron valence shells for an element equals the Period number. LINK Groups or Families are read • The number of valence LINK electrons are the same as the group number except: • RULE DOESN’T APPLY TO TRANSITION METALS grps 3-12 • Rule is the group number minus 10 for grps 13-18
- 28. Metals • LEFT sideof the zig-zag line • Few electrons in the outer Energy level • Most are solid at room temperature (not Mercury) • Shiny • Ductile (good conductors of electrical current) • Malleable (can be flattened with a hammer) • Conductors of thermal energy
- 29. Nonmetals • RIGHT sideof the zig-zag line • Almost a complete set of electrons in outer level • (Group 18 are Noble Gases: have a complete set of electrons & are stable) • ½ are gases at room temperature • NOT malleable • NOT shiny • POOR conductors of thermal energy & electric current
- 30. Metalloids • Semi-conductors • Borderthe zig-zag line • ½ complete set of electrons in outer valence • Have properties of metals and nonmetals
- 31. METALLIC LESS NOTMETALLIC LEFT RIGHT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
- 32. REACTIVITY CHANGES ACCORDINGTO NUMBER OF VALENCE ELECTRONS1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
- 33. Elements in thesame Group have similar properties. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
- 34. LAB: Color-Code the Periodic Table ofElements DIRECTIONS: Color-code the periodic table of elements as we take notes.
- 35. Alkali metals Group1 • Most reactive (outer valences have an extra electron it can give away) • Stored in oil (so won’t react with air & water) • NaCl (salt) • KBr (used in photography) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
- 36. Alkaline-Earth metals Group2 • Less reactive than group 1 • 2 outer level electrons • Magnesium is light-weight & strong for airplanes 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
- 37. 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Transition metals Groups 3-12 • Less reactive 2 outer level electrons • Metals: shiny, conduct thermal & electrical current
- 38. Lanthanides & ActinidesPeriods 6 & 7 • They are put at the bottom, because they would make the chart way too long if they were fit in • shiny, reactive metals; radioactive & unstable; labs 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
- 39. 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Boron Group Groups 13 • Aluminum is the most abundant metal in the crust • 1 metalloid • 4 metals • Reactive b/c of 3 electrons in outer level (wants to complete the set) • Solids at room temperature
- 40. 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Carbon Group Group 14 • 1 nonmetal (carbon) makes compounds proteins, fats, carbs • 2 metalloids (silicon, germanium) in computer chips • 2 metals (tin) not reactive • 4 electrons in outer level • Reactivity varies • Solids at room temperature
- 41. 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Nitrogen Group Group 15 • 2 nonmetals, 2 metalloids, 1 metal • 5 electrons in outer valence • Solids at room temperature (except Nitrogen) • Nitrogen is not reactive 80% of air; N + H combine to make ammonia fertilizers • Phosphorus: very reactive
- 42. 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Oxygen Group Group 16 • 3 nonmetals, 1 metalloid, 1 metal • 6 electrons in outer valence • Reactive • All but 0xygen are solid at room temperature; 20% of air; burns • Sulfur: sulfuric acid most commonly used compound in chemical industry
- 43. 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Halogen Group Group 17 • Nonmetals • 7 electrons in outer valence so… • VERY reactive (it only needs one more to complete the set) • Poor conductors of electrical current • Violent reactions with alkali metals to form salts • Never in uncombined form in Nature • Halogen + metal = salt chlorine, iodine are disinfectants
- 44. 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Noble Gases Group 18 • Nonmetals • 8 electrons in outer level (except Helium has 2) • STABLE (full shell) • Colorless, odorless gases at room temperature • Atmosphere is 1% argon, but most noble gases are rare
- 45. 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 Hydrogen • 1 electron • Reactive • Colorless, odorless gas at room temperature, low density (floats) • Explosive reactions with Oxygen • In stars, rocket fuel • Most abundant element in the Universe
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- 47. 2. Periodic TableElements VIDEO LOOP (9 min) 3. Crash Course Chemistry: Electron (10 min) 1. Elements VIDEO SONG (3 min)