1 / 28

Unit 4: The Periodic Table and Periodicity

Chemistry. Unit 4: The Periodic Table and Periodicity. Outline. The Elements. Element names come from a variety of sources. Sn,. C,. Cu. elements known to the ancients…. S,. Cf,. Am,. Sc. Eu,. place names…. Fr,. Po,. Ge,. No,. Rf,. Bh. Md,. Es,. famous people…. Cu. Fe,.

clio
Download Presentation

Unit 4: The Periodic Table and Periodicity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chemistry Unit 4: The Periodic Table and Periodicity Outline

  2. The Elements Element names come from a variety of sources. Sn, C, Cu elements known to the ancients… S, Cf, Am, Sc Eu, place names… Fr, Po, Ge, No, Rf, Bh Md, Es, famous people… Cu Fe, Au, Ag, foreign languages… W, Pb, Ti mythology-related names… Th, names related to element properties… Hg

  3. Mendeleev Moseley Background on the Periodic Table Dmitri Mendeleev: given credit for Periodic Table (~1870) -- organized Table by increasing atomic mass -- left spaces and predicted properties of undiscovered elements Henry Moseley: put elements in order of increasing ____________. atomic number

  4. 18 1 16 17 14 15 13 1 2 2 12 3 4 5 6 8 10 11 7 9 3 4 5 6 7 Describing the Periodic Table periodic law: the properties of elements repeat every so often period: horizontal row; there are 7 group (family): vertical column; there are 18

  5. lustrous (shiny) malleable (can hammer into shape) ductile (can pull into wire) good conductors (heat and electricity) Regions of the Table metals: left side of Table; form cations properties:

  6. Regions of the Table (cont.) nonmetals: right side of Table; form anions good insulators gases or brittle solids properties: neon sulfur iodine bromine Ne S8 I2 Br2

  7. nonmetals metals computer chips Si and Ge Regions of the Table (cont.) metalloids (semimetals): “stair” between metals and nonmetals (B, Si, Ge, As, Sb, Te, Po) properties: in-between those of metals and nonmetals; “semiconductors” computer chips

  8. group 1 (except H); 1+ charge; very reactive alkali metals: group 2; 2+ charge; less reactive than alkalis alkaline earth metals: group 17; 1– charge; very reactive halogens: noble gases: group 18; no charge; unreactive lanthanides: elements 58–71 contain f orbitals actinides: elements 90–103 coinage metals: group 11 (part of the transition metals) groups 3–12; variable charges; d block transition elements: main block (representative) elements: groups 1, 2, 13–18; s and p block

  9. actinides alkali metals coinage metals (part of the transition metals) alkaline earth metals halogens transition elements metalloids noble gases lanthanides main block elements more nonmetals hydrogen more metals

  10. Honors • Trans-uranic Elements • Elements with an atomic number greater than 92. www.chemicool.com • Complete data table as a group of two, defend your decision using the form. You may write your defense in essay form if needed. Be specific and answer all guiding questions. • Due next Wednesday, Jan. 15, 2014

  11. Einsteinium (Es) Albert Einstein • Relativity • E = mc2 • Offered Presidency of Israel • Element 99 • Photoelectric effect • Solar calculator

  12. Curium (Cm) • Madame Curie • Pioneer in radioactivity • (Ra = radium) • 25 pounds of pitchblende ore yields 1/1000 of a gram of radium • Emits 2 millions times as much radiation as uranium • (Rn = radon gas) • Discovered 5 elements • Nobel Prize (5 in Curie family) • Born in Poland • (Po = polonium) Marie Curie (1876–1934)

  13. Radium (Ra) Radium was used as a fluorescent paint on watch dials. It was applied with thin brushes that workers would lick to keep a fine tip. Many people died from the exposure to radium.

  14. Radon Gas Zone 1 counties have a predicted average indoor radon screening level greater than 4 pCi/L (pico curies per liter) (red zones) Zone 2 counties have a predicted average indoor radon screening level between 2 and 4 pCi/L (orange zones) Zone 3 counties have a predicted average indoor radon screening level less than 2 pCi/L (yellow zones) Radon gas occurs naturally from the radioactive decay of radium. Radium is found in small amounts in rock. Ra  Rn + radiation Predicted fraction of homes over 4 picocuries/liter radon http://www.epa.gov/radon/zonemap.html

  15. Nobelium (No)Element 102 Inventor: dynamite (TNT) blasting gelatin Nobel Prize Trinitrotoluene Alfred Nobel “Merchant of Death”

  16. Seaborgium (Sg) Glenn Seaborg • Separated f-block from rest of periodic table • Worked on Manhattan Project (Atomic bomb) • Classified until after WW II • Element 106 • Only living person to have an element named for them

  17. Silicon vs. Silicone • Silicon (Si) element • Silicone (…Si – O – Si…) polymer • Sealant (caulk) prevents leaks • Breast augmentation No cause-and-effect relationship exists between breast enlargement and breast cancer. Only one researcher found a causal link.

  18. 12 Mg 24.305 Magnesium Atomic Mass 24 amu melting point = 650oC (1202oF) silver gray metal used in flash bulbs, bombs,and flares 8th most abundant element (2.2% of Earth’s crust) lack of Mg produces same biological effect as alcoholism (delirium tremens)

  19. Mendeleev’s Work! • http://www.screencast.com/t/kg5WRCqrqcUh

  20. Periodicity The quality of being periodic; tendency to recur at regular intervals. Electro negativity Tendency of an atom to attract electrons towards itself.

  21. Li Na Same number of valence e– = similar properties Li Na 1s22s1 1s2 2s2 2p63s1 In any group, the element BELOW has one more occupied energy level than does the element ABOVE. Li Na The period that an element is in is the same as the energy level that its valence electrons are in. in 2nd period in 3rd period v.e– in 3rd E.L. v.e– in 2nd E.L.

  22. …increases as we go …decreases as we go Periodicity there are trends in properties of elements -- left-right AND up-down trends atomic radius: the size of a neutral atom WHY? add a new energy level each time WHY? it has to do with… coulombic attraction: attraction between (+) and (–)

  23. amount of charge distance between charges 2– 2– 2+ 2+ 2+ 2– 1– 1+ As we go , more coulombic attraction, no new energy level, more pull, smaller size – + + + – – Coulombic attraction depends on… + – – + H He

  24. v.e– v.e– Li K As we go , shielding effect increases. shielding effect: kernel e– “shield” valence e– from attractive force of the nucleus tougher to remove easier to remove -- caused by kernel and valence e– repelling each other

  25. Ca Cl Cl1– Ca2+ ionic radius: the size of an ion cations anions Ca atom Ca2+ ion Cl1– ion Cl atom 17 p+ 20 p+ 17 p+ 20 p+ 17 e– 18 e– 20 e– 18 e– cations are smaller anions are larger

  26. removes 1st e– M + 2nd I.E. M + 3rd I.E. As we go , 1st I.E…. As we go , 1st I.E…. ionization energy: the energy required to remove an e– from an atom M + 1st I.E. M1+ + e– M2+ + e– M3+ + e– Each successive ionization requires more energy than the previous one. decreases. (due to the shielding effect) increases.

  27. As we go , electronegativity… As we go , electronegativity… electronegativity increases electronegativity: the tendency for a bonded atom to attract e– to itself Linus Pauling quantified the electronegativity scale. decreases. increases.

  28. Summary of Periodic Trends

More Related