WARM UP 10-16-15

1. These ions gained or lost electrons: Na+ and O2-

2. What is the difference between cation and anion? Give an example of each.

3. Write the ion form for these atoms: Indium, Sulfur, Fluorine and Calcium.

AgendaNew seatsExtra CreditOnline bond labNotes Unit 4-2Finish the Robinson

HomeworkOct 24 - Saturday SchoolOct 29 - Xtra Credit

EXTRA CREDIT Due Oct 29 Up to 1% of overall grade Read and write a report on 4 different

news articles

ONLINE BOND LAB 1 laptop per group (3-4 students) Google “chemical bonds PBS” Click on the first link and then “launch” Follow instructions on your hand out for

each tab on the site

UNIT 4-2CHEMICAL BONDS

IONIC BONDS

Electrons are transferred Metal and Non-metal ions of opposite

charge Soluble (dissolve) and dissociate in

water Conduct electricity in water

IONIC BONDS High melting and boiling points Can form hard crystals Rarely burn (not flammable) Brittle (because of the strong

attraction between the charges)

IONIC BONDS

crystal lattice structure made up of (+) and (-) ions

COVALENT BONDS Electrons are shared Nonmetal and Nonmetal Occur in large biological molecule (protein,

DNA) Some dissolve (not all), but do not dissociate (come apart)

COVALENT BONDS Low melting and boiling points Do not conduct electricity Variety of textures Usually burn (flammable)

COVALENT BONDS 2 types: Nonpolar covalent bond – when

electrons are shared equally between the elements

Polar covalent bond – when electrons are attracted to one element in a compound. Giving one side a slight (–) charge and the other a slight (+) charge

COVALENT BONDS Electronegativity is used to

determine if a compound is polar. The Greek symbol delta is use to

signify partial charge ( )

METALLIC BONDS Metal atoms only Do not dissolve Electrons move around

freely Conduct electricity Hard and Malleable

(can bend and dent)

CHECK IN What kind of bonds are in the following

compounds?

Ag C2H6

MgCl2

BOND IDENTIFICATION LAB Objectives: Classify compounds as having

ionic or covalent bond based on its physical property: solubility, conductivity and melting point

Procedure:1. Obtain the chemicals (half of a well)2. Set up the apparatus and label your

aluminum foil using a pencil3. Put the chemicals on top of the aluminum

foil and apply heat to it4. Record the melting order5. Dissolve the chemicals in water and

ethanol