Name Objectives: Per. Electrons and Periodic Table (Ch. 4 & 5) OTHS Academic Chemistry Express the arrangement of electrons in atoms through electron configurations Understand the electromagnetic spectrum and the mathematical relationships between energy, frequency, and wavelength of light Calculate the wavelength, frequency, and energy of light using Planck's constant and the speed of light Explain the use of chemical and physical properties in the historical development of the Periodic Table Use the Periodic Table to identify and explain the properties of the chemical families Use the Periodic Table to identify and explain periodic trends Vocabulary: electron configuration, frequency, amplitude, energy, wavelength, direct, inverse, electromagnetic spectrum, energy level, sublevel, orbital, valence electron, octet, ion, cation, anion, electronegativity, ionization energy, atomic radius, ionic radius, period, group, shielding effect, transition metal, alkali metal, alkaline earth metal, metalloid, halogen, noble gas, lanthanide, actinide. Topics to master: Provided: The electromagnetic spectrum Wave calculations Periodic table Aufbau Principle vs. Pauli Exclusion Principle vs. Hund s rule c = f λ Electron configurations c = 3.00 x 10 8 m/s Orbital diagrams Ion formation with dot diagrams E = hf Periodic families and their properties h = 6.626 x 10 34 J. s History of the periodic table- Mendeleev, Moseley, Seaborg Periodic trends- Ionic & atomic radius, electronegativity, and ionization energy CHECKLIST: How to be successful in OTHS Academic Chemistry Pay attention and take notes in class Ask questions in class on material that is not clear Work every page in the practice packet for the unit Check answers to the practice packet online at http://othschem.weebly.com/ Come to tutorials with any chemistry teacher Do the online homework and check solutions once they become available Always do the practice test for every test & ask good questions on review day Keep up with the calendar for the class/be aware of approaching quizzes, tests, & other deadlines Use videos posted on website as a quick and convenient tutorial Read the chapter in the book pg1 pg2 pg3 pg4 pg5 pg6 pg7 pg8
Wave Worksheet Part 1 c = λ f c = speed of light = 3.00 x 10 8 m/s wavelength (λ) should be expressed in meters (m) frequency (f) should be expressed in reciprocal seconds (s -1 or Hz) 1. What is the frequency of radiation with a wavelength of 3.82 x 10-7 m? What part of the electromagnetic spectrum does this fall in? 2. What wavelength of radiation has a frequency of 3.40 x 10 18 Hz? What part of the electromagnetic spectrum does this fall in? 3. What is the frequency of red light if the wavelength is 7.60 x 10-7 m? 1
4. The green light associated with the aurora borealis is emitted by excited oxygen atoms. Its wavelength is 5.58 x 10-7 m? What is the frequency of this green light? 5. Gamma rays have frequencies around 1.0 x 10 21 Hz. What wavelength does this correspond to? Part 2 E = h f h = Planck s constant = 6.626 x 10-34 J. s 6. How much energy does a photon of light with a frequency 4.2 x 10 8 Hz have? What part of the electromagnetic spectrum does this fall in? 7. It takes 6.63 x 10-18 J of energy to eject an electron from a certain atom. What frequency of light is this? What part of the electromagnetic spectrum does this fall in? 8. What is the energy of a photon of light with a wavelength of 6.10 x 10-7 m? Hint: you need to use the equation from Part 1 also! What color is this light? 2
Electron Configuration 1. Give the electron configuration for the following elements: ***The noble gas configuration can be used after oxygen He Si Be Ni O As Na Sn Al Bi Ar Ba Sc Cd 2. Identify the specific element (symbol) that has the following electron configuration: ls 2 2s 2 2p 1 [Ne] 3s 2 3p 5 [Ne] 3s 2 3p 3 [Ar] 4s 2 3d 10 4p 4 [Ar] 4s 1 [Kr] 5s 2 4d 10 5p 6 [Ar] 4s 2 3d 10 ls 2 2s 2 2p 5 [Kr] 5s 2 [Xe] 6s 2 4f 14 5d 10 6p 5 [Ar] 4s 2 3d 10 4p 2 [Kr] 5s 2 4d 2 [Xe] 6s 1 [Ar] 4s 2 3d 6 3
LEVELS, SUBLEVELS, ORBITALS, AND ELECTRONS 1. Which energy level a. holds a maximum of eight electrons? b. contains only an s sublevel? c. is the first to have s, p and d sublevels present? d. is the first to have a f sublevel? 2. Which sublevel(s) are present in a. the first energy level? b. the third energy level? c. the fourth energy level? 3. How many orbitals are in a. the first energy level? b. the s sublevel in the second energy level? c. the p sublevel in the fourth energy level? d. the third energy level? e. the d sublevel in the fifth energy level? 4. How many electrons (maximum number) may be placed in a. the second energy level? b. the s orbital in the fourth energy level? c. the d sublevel in the third energy level?. d. one f orbital? e. a 3p orbital? f. a 3p sublevel? g. one p orbital? 4
Ions Ion Formation Worksheet The name s Bond, Ionic Bond. I like my electrons taken, not shared. An ion is a charged particle formed by loss or gain of electrons. Atoms form ions in order to attain a stable octet (8 valence electrons) in the outer energy level. When an atom LOSES electrons, this results in a positively charged ion (CATION). When an atom GAINS electrons, this results in a negatively charged ion (ANION). Element e- dot structure Lose or gain e-? How many? Ion formula w/ charge Mg Mg Lose 2 Mg 2+ (1) Electron configuration of atom (2) Electron configuration of ion (1) Mg= 1s 2 2s 2 2p 6 3s 2 (2 valence e-) (2) Mg 2+ = 1s 2 2s 2 2p 6 (8 valence e-) Al S Na Cl Ionic Compound Formation: Simple ionic compounds are formed when a metal loses electrons to a nonmetal. Then the two newly formed + and ions attract. Complete electron dot diagrams for the following combinations, showing transfer of electrons with arrows. (a) Mg and S (b) Na and S (c) Al and Cl 5
SUMMARY OF PERIODIC AND GROUP TRENDS TREND ATOMIC RADIUS / IONIC RADIUS DOWN A GROUP IONOZATION ENERGY / ELECTRONEGATIVITY ACROSS A PERIOD Reason: Increasing Energy levels DECREASES Reason: Reason: Increasing shielding effect INCREASES Reason: Write in the patterns that the trends follow on the periodic table below: *Note: Noble gasses are NOT electronegative! Fluorine (F) is the most electronegative element. TRENDS IN IONIC RADIUS FOR THE SAME ELEMENT A POSITIVE ion is a CATION. It is a METAL that has LOST electrons. POSITIVE ions are SMALLER than the neutral atom. Examples: Na + is than Na A NEGATIVE ion is an ANION. It is a NON-METAL that has GAINED electrons. Negative ions are LARGER than the neutral atom. Examples: F is than F 6
Atomic Radius Worksheet: Periodic Trends Circle the correct answer 1. a. Atomic radius increases / decreases going down a group. b. Atomic radius increases / decreases going left to right across a period. 2. a. Which element has the larger atomic radius? i. Ca or Ba iii. Rb or K ii. Ca or Br iv. B or F b. Which element has the smaller atomic radius? Ionic Radius i. Fe or Zn iii. Xe or Ne ii. Br or I iv. Na or Al 3. a. A positive ion (cation) like Na + is always smaller / larger than the neutral metal atom (Na). b. A negative ion (anion) like F is always smaller / larger than the neutral nonmetal atom (F). 4. Which has the larger radius? i. K or K + iii. O or O 2- ii. Ca or Ca 2+ iv. Cl or Cl - 5. a. Ionic radius increases / decreases going down a group. b. Ionic radius increases / decreases going left to right across a period. 6. Which has the smaller ionic radius? i. Ca 2+ or Ba 2+ iii. Rb + or Sr 2+ ii. Cl - or Br - iv. N 3- or F - 7
Ionization Energy 7. a. Ionization energy increases / decreases going down a group. b. Ionization energy increases / decreases going L to R across a period. 8. a. Which element has the greater ionization energy? i. Si or Cl iii. Ga or Br ii. Si or Pb iv. Li or Cs b. Which element has the smaller ionization energy? i. C or Sn iii. P or Bi ii. Ba or Au iv. Be or O Electronegativity 9. a. Electronegativity increases / decreases going down a group. b. Electronegativity increases / decreases going L to R across a period. 10. a. Which element has the greater electronegativity? i. Cl or Al iii. N or As ii. K or Fr iv. Li or F b. Which element has the smaller electronegativity? i. Hg or Pb iii. Cr or W ii. Be or Ba iv. Sb or I 11. Group trends identified for the previous properties of the elements can be explained by a particular principle, the. (Use your notes to identify it!) 12. Periodic trends identified for the previous properties can be explained by another principle, increasing. (Use your notes!) 8