Catalyst Draw the ionic compound that results from combining Magnesium and Chlorine. Draw the ionic compound that results from combining Calcium and Permanganate (MnO 4 - ) End

Homework Review and Entry Slip

Entry Ticket 1.What is the compound that forms between barium and oxygen? 2.What is the compound that forms between magnesium and NO 3 -1 ? 3.How are crystal lattices arranged?

Rate Yourself! Using your exit ticket score, rate yourself 1 – 4 on LT 2.1, 2.2, 2.3, and 2.4

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LECTURE 2.3 – CRYSTAL LATTICES, COVALENT BONDS, & LEWIS STRUCTURES

Today’s Learning Target LT 2.4 – I can explain how electrostatic attractions lead to the formation of visible salt crystals. In this explanation, I can incorporate the idea of electrostatic attraction, positive charge, and negative charge.

How do ions arrange themselves in salt crystals?

I. Crystal Lattice Ionic compounds arrange charged ions in repeating pattern to form crystal lattices. Salt crystals that we see are repeating structures of a very simple unit.

NaCl Structure

II. Electrostatic Attraction Positive ions are attracted to negative ions This attraction holds crystal lattices together. This attraction is known as electrostatic attraction

Electrostatic Attraction

SUMMARIZE

Today’s Learning Targets LT 2.6 – I can identify a compound containing a covalent bond and discuss how electrons aid in the formation of covalent bonds. LT 2.7 – For a given covalent compound, I can draw a Lewis Dot diagram for the compound and explain how it illustrates the covalent bond.

W HAT ARE COVALENT BONDS ?

Chemical Bonding Ionic Bonds Metallic Bonds Covalent Bonds

I. Covalent Bonding This is a bond between only non-metals. In a covalent bond, the electrons are shared between the elements so that each can get an Octet. Most molecules in biology are covalent compounds

COVALENT BONDS PLAY WELL TOGETHER

How do you show electrons being shared?

Covalent Bonds Share!

II. Electronegativity and Covalent Bonding Because electrons are not completely transferred, covalent bonds form between molecules that have similar electronegativities This is why metals cannot form covalent bonds.

Lewis Structures for Ionic Bonds Na Cl

Lewis Structures for Ionic Bonds [Na] + [Cl] -

Chemical Bonding Ionic Bonds Metallic Bonds Covalent Bonds

II. Drawing Lewis Structures Halogens and hydrogen form only one bond and are located at the end of a molecule. The central atom is always carbon (if it is present) and/or the element that has the lowest electronegativity.

Class Example Draw the Lewis structure for H 2 S

My Turn! Draw the structure for NH 3

Stop and Jot Draw the Lewis structure for C 2 H 6

III. Single, Double and Triple Bonds Elements can share more then one set of electrons. They can also form double and triple bonds. Single bond = 2 electrons Double bond = 4 electrons Triple bond = 6 electrons

Class Example Draw the Lewis Structure for CH 2 O

My Turn! With your table, draw the structure of C 2 H 2

Stop and Jot Draw the structure of HCN

SUMMARIZE

Collaborative Activity: Investigate and Check At your table number off 1 through 4 Odd numbers (1 & 3) will solve problems in the left column. Even numbers (2 & 4) will solve problems in the right column After a pair solves a problem they will pass the problems to another pair to check that they did the problem correctly. Work through the problems in order.

Practice Benchmark and Good News No history of scientists! (That means you don’t have to remember what Thomson, Bohr, Rutherford, and Dalton said) You still have to know how to solve problems using their concepts though! Breakdown of questions on next slide! Practice benchmark will be given Thurs/Fri as your quiz for Unit 2 to test how well you would do on your benchmark. Prepare for it!

Practice Benchmark and Good News

STOP LIGHT CARDS Take your index card and color in a stop light exactly like this: On the reverse side, shade it in blue! As class goes on, you will put the paperclip on the color that corresponds to your level of understanding!

Note Taking Take notes using the powerpoints/video lectures, or complete your in class notes (if you choose to take them)!

Exit Ticket 1.Draw the Lewis structure for H 2 O 2.Draw the Lewis structure for NH 3 3.Draw the Lewis structure for HCN

Rate Yourself! Using your exit ticket score, rate yourself 1 – 4 on LT 2.1, 2.2, 2.3, 2.4, 2.6, and 2.7

Closing Time Homework 2.4 – Lewis Structure Practice Unit 2 Test Soon!