Periodic Trends and Electron Configuration

Answer KEY Unit 3 Outline/ Study Guide - Electron Configuration and Periodic Trends ionization energy, electronegativity, and the relative sizes of ions and atoms (this includes knowing the definitions of ionization energy, electronegativity, cation, and anion.) Study Guide -(use your notes and worksheets for a more complete review) 1. Identify the following things on the periodic table: -metals metalloids (semimetals) transition metals nonmetals -Periods -alkali metals alkaline earth metals halogens -noble gases Groups/ families Identify groups with the following numbers of valence electrons: 1,2,3,4,5,6,7,8 2. Why do the elements in the groups (columns) behave so similar to each other even if they have great differences in their number of protons? same number of valence electrons and similar chemical properties. 3. What is the connection between the following terms: octet rule, valence electrons, and ions? In order to achieve the octet rule, atoms gain or lose their valence electrons. They become charged ions when this occurs. 4. a. List the elements that are exceptions to the octet rule b) Why don’t these atoms achieve the octet rule? a. Small atoms are happy with 2 electrons (ex: H, He, Li, Be, B) b. because the 1s energy level only holds 2 electrons 5. a. Isotope or Ion atoms that have a different number of neutrons b. atoms have gained or lost electrons Ion Isotope c. shown by putting a +/- sign next to an element (ex: Ca + 2) d. shown by putting the mass in hyphen notation (ex: C- 14) Ion Isotope 6. a. Which electron orbital has more energy, electrons in 3p or 5p? Energy Level 5 has more energy because it’s further away from the nucleus & requires more energy to put an electron there. b. What atomic sublevel has the next highest energy after 2p and will fill next? 3 s. c. Based on your lab experience, how does an electron become excited? They gain energy from the Bunsen burner d. When do you see the unique light pattern for each element? when the electrons fall back down to a lower energy level they release the energy in the form of light. 7. a. Cation or anion? How do you know? b. Did they gain or lose electrons? How do you know? c. Which atom is larger or smaller in size? How do you know? O -2 Mg + 2 Anion- negative charge Cation- positive charge Gained 2 more negative electrons, thus they are more negative by 2 Bigger, gained electrons Lost 2 electrons, thus they are more positive Smaller, lost electrons 8. Noble Gas Config. [Ne]3s23p5 [Xe]6s24f145d106p3 [Ar] 4s23d104p5 [Ar]4s1 [Xe]6s24f145d106p4 9. # valence electrons period block Group number 7 5 7 1 6 3 6 4 4 6 P P P S P 17 15 17 1 16 Ion it will form Cl-1 Bi-3 Br-1 K+1 Po-2 Element name Cl Bi Br K Po How many valence electrons does each of the following elements have? a. noble gases= 8 b. alkali metals=1 c. halogens= 7 d. alkali earth metals= 2 10. energy it takes to remove an electron from an atom (Lowest= Fr Highest= He) A. Ionization energy: b. Identify the elements that have the highest & lowest ionization energy Na, Cl, Mg, P K, Na, Rb, Li highest: lowest: highest: Cl 11 A. Electronegativity: Highest= F) Na Li lowest: Rb an atoms ability to attract electrons to itself. (Lowest= Fr b. Identify the most & least electronegative elements Na, Ne, O, Al Most: least: Ca, Cu, F, Ar most: least: O F Ne Ar size of the radius of the atom (it’s actually defined as ½ the distance between the nuclei of two atoms bonded together) (Biggest= Fr smallest= He) 12. Atomic radius: b. Identify the largest to smallest atoms based on atomic radius Ti, P, Cs, Ne Li, O, Cu, K largest: smallest: largest: smallest: Cs O Ne K Naming/ Formulas: 13. A. What is the rule for naming/ formula writing for a metal + non-metal? Full name & then Root + -ide ending. Formula writing= swap & drop the ion charges. b. Give an example: CaCl2 Calcium chloride 14. What is the rule for naming/ formula writing for 2 non-metals? Prefix (except if only one) + full name & then Prefix + root + -ide ending b. Give an example: N2O3 Dinitrogen trioxide