150 likes | 308 Vues
E L C T R O N C O N F I G U R A T I O N. & A T O M I C P R O P E R T I E S. 11.4. Period 5 Group #2. CHEMISTRY JOKES. Two atoms are walking down the street. Says one atom to the other, "Hey! I think lost an electron!" The other says, "Are you sure??"
E N D
E L C T R O N C O N F I G U R A T I O N & A T O M I C P R O P E R T I E S 11.4 Period 5 Group #2
CHEMISTRY JOKES Two atoms are walking down the street. Says one atom to the other, "Hey! I think lost an electron!" The other says, "Are you sure??" "Yes, I'm positive!“ A small piece of ice which lived in a test tube fell in love with a Bunsen burner. "Bunsen! my flame! I melt whenever I see you" said the ice. The Bunsen burner replied :"It's just a phase you're going through".
A. Electron Arrangements in the first 18 Atoms on the Periodic Table • Electron configuration: arrangement of electrons in an atom. • Orbital diagram: represent the configuration. • Box diagram: orbitals = boxes grouped by sublevels with arrows that show direction the electron spins & indicates the electron. • Valance electrons: outermost electrons in atoms • Core electrons: innermost electrons (closest to the nucleus).
A. Electron Arrangements in the first 18 Atoms on the Periodic Table Example: What is an orbital diagram also called?
B. Electron Configuration and the Periodic Table • Atomic energy levels are broken down into principal level (n) which contains various number of sublevels • Wave mechanical model-atoms arranged in orbitals (2 electrons each) • Valence electron configuration recur going from one level to another • To find the electron configuration for an element: put electrons starting from lowest energy level (s) and fill up each orbital according to the periodic table until there are no more electrons • Ex. What is the orbital shape for Lanthanides? F
C. Atomic Properties and the Periodic Table • Science based on observed properties of substances • Observation remains the same but theories change as we gain better understanding • Ex. Why do theories change over time?
D. Metals and Nonmetals • Metals: tend to lose electrons to form positive ions, lustrous appearance, ability to change shape without breaking and conduct heat and electricity (left of table) • Nonmetals: gain electrons to form negative ions; some can conduct electricity (right of table) • Metalloids (semimetals): exhibits both metallic and nonmetallic traits • Ex. What kind of ions do metals and nonmetals form?
Atomic size and ionization energy • Atomic size increases as it goes down a group and decreases across the periodic table. • Ionization energy:energy required to remove an electron from the atom. • Ionization energy decreases down a group and increases across the period. • Metals have low ionization energy level while nonmetals have high ionization energy level. • Quiz: where will an element that has a high ionization energy level be found.
Quiz! • 1. What is the difference between valance electrons and core electrons? • 2. Which way does ionization energy generally go as it moves down a group? • 3. Write the electron configuration for Potassium. • 4. What is the purpose of the wave mechanical model? • 5. Why do particular valence electron configurations recur periodically?
Answer key • 1. Valence electrons are the outermost principal energy level of an atom, while core electrons are the innermost and are not involved in bonding atoms to each other. • 2. [Ar] 4s1 • 3. f • 4. build up the atoms • 5. Why do particular valence electron configurations recur periodically?
References • www.coolscience.org/coolscience/cooljokes/chemjokes.htm • http://edusolution.com/regentsquiz/chemistry/quiz/ques25.gif • www.mikeblaber.org/oldwine/chm1045/notes/Struct/EPeriod/Struct09.htm • http://media-2.web.britannica.com/eb-media/39/7339-004-23335A52.gif • www.shodor.org/chemviz/ionization/students/background.html