September 13, 2010
 Homework
 Chp 3 study Guide (download) & notes due wed
 Write a response to “Radioisotopes” essay prompt.

You may use your book or other resource for ideas
 Objectives
 Use models to review basic chemistry
 BellRinger
 Draw an oxygen atom and label: electron, proton,
neutron, nucleus, and orbital
Atomic Modeling
 Draw an image similar to transparency on half of paper
 Use the info in the periodic table to make a helium atom
using drawing and beads
 How many of each subatomic particle do you need? How
can you use the periodic table to help? (review atomic #
and atomic mass)
 Draw the atom in your notes
 What would happen if you altered the #of each particle?
 Electron=charged ion
 Proton=new element
 Neutron= isotope
Orbitals
 How many electrons can fit in each orbital?
 Practice with C, N, O, and F
 How does proton # compare with e #?
 What is the relationship btwn stability of the atom and the
number of electrons in the valence shell?
 How many more e- does each element need to become stable?
 What happens to the stability of the atom as you move left
to right on the periodic table? (take notes on p. table)
 Electronegativity increases
 Which elements are the most stable?
 Which are the most reactive?
Learning Check
 What determines the chemical behavior of an atom?
 Give an example of two atoms that have different
chemical behaviors and explain the cause of their
difference
Ionic Molecules
 Draw a second atomic model on the paper
 Create an fluorine atom (7) and an hydrogen atom
 What can you say about the stability of each atom?
 What would make each one more stable?
 What type of bond is being formed?
 Move the beads to make each one stable
 Draw a before and after in their notes
 Do the same with 3LiCl,
MgO,
and BeS
17
12
6
4 16
(atomic numbers)
Ionic Bonds
 Label cation and anion for each molecule (cations-Li,
Mg, Be; anions Cl, O, S)
 Look at trends in p. table…which elements tend to
become neg? Why? Positive? Why? (relate back to
electronegativity)
 Which columns combine to form ionic bonds? Why?
 Why don’t all of the elements form ionic bonds? (not
enough e.neg to steal or too much e.neg to give away
electrons)
 So what do those atoms do?
Learning Check
 What conditions must be present in order form an
atom to form an ionic bond with another atom?
 Using the periodic table and your notes, provide an
example of 2 atoms that would likely form an ionic
bond (you can’t use one we did in class).
 Explain which element is the cation and which is the
anion
 Describe how the electronegativity of each allows it to
react with the other atom
September 14, 2010
 Homework
 Complete Chp 3 Study guide and notes
 Objectives
 Use models to review basic chemistry
 Peer edit a free response essay using a rubric
 BellRinger
 What do atoms that cannot form ionic bonds do to
become stable?
Covalent bonding
(Students will need to be able to overlap their atomic models)
 Make two hydrogen models
 Will these form an ionic bond? Why not?
 What is their only option? (share the e-)
 Slide the models together, overlapping the shell so that
they share the 2 e Draw and explain the process in your notes
 Practice with CH4 and NH3
 Try double bonds with paper models
 Show how O2 and CO2 covalent bonding can be
demonstrated with candy models
Learning Check
 Explain how valence electrons influence molecular
bonding
 Explain how electronegativity influences molecular
bonding
Hydrogen Bonding
 Make CH4, C2H6, C3H8, O2, and CO2 candy models
Ethane
propane
 How many bonds can H make? O? C?
 Make 2 H2O, and 1 each H2, O2, NH3, and CH4
 Which molecules are symmetrical?
 Polar vs. Non polar?
 Relationship btwn symmetry and polarity?
 Relationship btwn e.negativity and polarity?
 Arrange the H2O molecules according to polarity
 Draw a dotted line btwn neg and pos poles to show H
bonding
Learning Check
 Complete the “Comparing molecular bonds” handout
Free Response Essay
 Use the provided rubric to grade a classmates essay.
 Give them a score out of 10 based on the guidelines
provided.
Summary
 What seems to be the most important things to
remember when writing free response essays?
 Homework
 Complete Chp 3 Study guide and notes