Drill #18 Jan. 8 & 9, 2013 Take your time, do your own work, and draw the Lewis structure for HCN. Now, tell me the shape of this molecule.

Agenda Molecular Geometry Quiz Review Practice Problems Review Worksheet – due on Friday!

Objectives For a complete listing of Midterm objectives, see the Midterm County Assessment Teacher’s Guide.

Topics Covered Chapter 1 (Measurements) Chapter 2 (Energy & Matter) Chapter 3 (Atomic Structure) Chapter 4 (Electron Configurations) Chapter 5 (The Periodic Table) Chapter 6 (Groups of Elements) Chapter 7 (Chemical Bonding/Formulas) Chapter 8 (Shapes of Molecules)

Chemistry Midterm Review

Practice Problem Identify the number of protons, neutrons, and electrons in the following ion: 34 Cl 1-

Answer 17 protons; 18 electrons; 17 neutrons

Practice Problem Identify the number of significant figures in the following measurements: (a) meters; (b) seconds; (c) ms; (d) 4500 cm

4 rules for determining sig figs Non-zero numbers are always significant Zeros between non-zero numbers are always significant Zeros that act as placeholders are not significant has 3 sig figs 4320 has 3 sig figs All zeros at the end are significant when there is a decimal point after an integer 6.20 has 3 sig figs

Answers a) 5 b) 2 c) 6 d) 2

Convert 254 cm to meters Convert 60 mg to kg King Henry Does Usually Drink Chocolate Milk Base Kilo hecto deka UNIT deci centi milli Practice Problems

Answers 2.54 m kg

Practice Problem Identify the number of protons, neutrons, and electrons in the following ion: 59 Ni 2+

Answers 28 protons 31 neutrons 26 electrons

Practice Problem Write the electron configuration using both sublevel notation and orbital diagram notation for sulfur.

Answer 1s 2 2s 2 2p 6 3s 2 3p 4

Practice Problem Which atom has the larger atomic radius: Ca, Sr, or Ba? Why? Which atom has the greatest ionization energy: Ca, Sr, or Ba? Why?

Answers Barium (Ba) – largest radius Calcium (Ca) – greatest ionization energy

Review What is an isotope? What is an ion?

Review Isotope = atoms of a particular element contain the same number of protons but may have a distinct number of neutrons. element protonsneutrons Ion = atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative charge.tommoleculeelectronsprotonscharge

Practice Problem Write the electron configuration using sublevel notation for strontium (Sr).

Answer 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2

Practice Problem Write the formulas for the following: (a) barium carbonate, (b) sodium phosphate, and (c) carbon tetrachloride

Answers a) BaCO 3 b) Na 3 PO 4 c) CCl 4

Review Question Name the following compound: Cu(BrO 3 ) 2

Answer Copper(II) bromate

Homework Complete page 1 of Review Sheet Due on Thursday!