Element of the Day Bk

Transcription

1 Element of the Day Bk Berkelium (bәr kee lee әm), is a transuranic radioactive chemical element with the symbol Bk and atomic number 97, a member of the actinide and transuranium element series. It is named after the city of Berkeley, California, the location of the University of California Radiation Laboratory where it was discovered in December Just over one gram of berkelium has been produced in the United States since There is no practical application of berkelium outside of scientific research which is mostly directed at the synthesis of heavier transuranic elements and transactinides. Berkelium is a soft, silvery white, radioactive metal. The berkelium 249 isotope emits low energy electrons and thus is relatively safe to handle. However, it decays with a half life of 330 days to californium 249, which is a strong and hazardous emitter of alpha particles. This gradual transformation is an important consideration when studying the properties of elemental berkelium and its chemical compounds, since the formation of californium brings not only chemical contamination, but also self radiation damage, and self heating from the emitted alpha particles. What orbitals do the valence electrons of Bk occupy? 1

2 Chemistry 1. Element of the Day 2. Review Homework 3. VSEPR Theory Notes 4. POGIL Activity 5. Start Homework Announcements Due Today: POGIL ACTIVITY and read pages and answer questions 57, 58, 64, 69, 74, 80, and 81. Due Monday: Finish POGIL Activity, briefly review Chapter 11, and begin work on your study guide. Extra Credit: Crossword Puzzle Due Monday 2

3 Review Homework 3

4 Electron Configuration Notes Key Terms Electron configuration Orbital diagram (box diagram) Valence electrons 4

5 Write the electron configuration for the following: 1. H 2. He 3. C 4. F 5. Ca How many electrons can fit into the 2 nd principal quantum level? How many electrons could be found in the 3 rd principal quantum levels? 5

6 Electron Configuration Notes Trends in the Periodic Table Metals Nonmetals Metalloids Ionization energy Electronegativity Representative elements Atomic Size 6

7 Lewis Dot Products In almost all stable chemical compounds of the representative elements, all of the atoms have achieved a noble gas electron configuration. Lewis structure: is a representation of a molecule that shows how the valence electrons are arranged among the atoms in the molecule. Octet rule: they are surrounded by eight electrons. Lone pairs: unshared electrons example: fluorine gas. Examples of Lewis Dot Structures: 1. H 2 O 2. NH 3 3. CO 2 7

8 VSEPR Model Notes Molecular Structure (Geometric Structure): Bond Angle: Shapes 1. Trigonal Planar Structure: 2. Tetrahedral Structure (Tetrahedron): 3. VSEPR Model: Example: 8

9 VSEPR Model Notes Steps for Predicting Molecular Structure Using the VSEPR Model 1. Draw the Lewis Structure 2. Count the electron pairs and arrange them in the way that minimizes repulsion (as far apart as possible). 3. Determine the postions of the atoms from the way the electron pairs are shared. 4. Determine the name of the molecular structure from the positions of the atoms. Example: CH 4 9

10 VSEPR POGIL Activity 10

11 Exit Question What molecular structure does NH4 have? Reminder Due Today: POGIL ACTIVITY and read pages and answer questions 57, 58, 64, 69, 74, 80, and 81. Due Monday: Finish POGIL Activity, review chapter 11 and begin work on your study guide. Extra Credit: Crossword Puzzle Due Monday 11