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Unit 4: Atomic and Molecular Models

Our last unit of the First Semester pertains to Models for understanding atoms and molecules. The unit begins with an exploration of quantum models of the atom and their value in explaining chemical and physical properties. The second half of the unit will look at the topic of bonding and make an effort to explain why ionic and molecular compounds form with their specific ratio of atoms.

Lab AMM2 Due Date

The due date has been set. Lab AMM2 - It's Periodic is due on Friday, December 20 by 8 AM. Drop your Google doc or Google Slide Presentation into the Google Classroom folder. Don't procrastinate just because the due date is way in the future. DO IT NOW! There is another Google doc Lab nearer the end of the unit.

Quiz Key on Atomic Models

The Unit 4 Quiz will be returned on Monday. Here is a link to the quiz key for the two nearly identical forms of the quiz.

View Quiz Key.

Lab Notebook Collection

Lab Notebooks will be collected on Wednesday, December 18 at the beginning of class. Lab AMM1 (Elemental Fingerprinting) and Lab AMM3 (Ionic vs. Covalent) and the PhET: Molecular Shapes Simulation should be in your notebook. The Scoring Guide used to grade these activities can be found online.  Labs AMM2 and AMM4 will be submitted digitally via Google Classroom by 8 AM on December 20.

View Unit 4 Lab Scoring.

The End is Near

End is nearOur Unit 4 Test has been rescheduled toWednesday, December 18. The test will cover all topics in Chapters 11 and 12. That's a lot of material.

An optional Review/Practice webassign will be posted and will prove to be an excellent review for the test. The questions have been taken from past assignments. A well-docmented packet is also a very good review tool.

The test will include approximately 25 Mulitple Choice Questions and five long-answer problems (diagramming/explaining). You will be allowed 60 minutes; extra time is not alloted.

You will be provided a Periodic Table, a table of electronegativity values, and a list of all the possible names for electron pair geometry and molecular geometry.

Lab AMM2 - It's Periodic

Lab AMM2 - It's Periodic is more of a data-analysis activity than it is an actual experimental lab. You will be provided data in a Google Sheet that you will manipulate and graph in order to identify trends in the data and relate such trends to the placement of the elements on the periodic table. In addition to identifying/describing the trends, you will also explain why the trends exist in terms of the electronic structure of the atoms of the various elements. You will produce a Google Doc or Slide Presentation that includes the three graphs, the descriptions of the trends, and the explanation of one of the trends. Directions for this lab and a link to the Google Sheet containing the data are included below.  Links to other pertinent information is also provided:

Three Models of Science

In your explanations of a periodic property, be sure to incorporate an understanding of the three HUGE models of science discussed in class. These models are the Periodic Law, Quantum Mechanics, and Coulomb's Law.

View: Three Models of Science

Coulomb's Law Help

Tuesday (11/28) included an admittedly brief overview of Coulomb's Law - the law of electrostatic interaction. Coulomb's Law is one model of science that helps us to understand the forces of attraction and repulsion involved with charged particles of atoms (electrons and protons). The basic concept will be important to understanding the explanations of why periodic properties are what they are. You can find some expanded help using the links below to our favorite Physics website.

Coulomb's Law Tutorial at The Physics Classroom

Coulomb's Law simulation at The Physics Classroom

Lab AMM2 Scoring

Lab AMM2 (or Data Analysis AMM2) will be graded with the rubric shown below:

Scoring Rubric

Atomic Interactions

Shown in class on Wednesday (12/4): Atomic Interactions from PhET

Mr. H's Little Secret

Pssss.  Hey bud! I have a secret to share. Now that you know how to calculate the molar mass, here's a little cheat you should be permitted to use. It's called a Molar Mass Calculator and you will find several by following the links below. You type in the formula and it calculates the molar mass.

WebQC Chemical Portal (one of my favorites)

EndMemo (allows formula or name entry)

Environmental Chemistry (scroll to bottom)

Molecular Weight Calculator by Lenntech

or Google, e.g. molar mass Al2(SO4)3

FREE: A Chemistry Study Tip

Stretching out your studies over a lengthy period of time so that there are many "visits" of the material is far better than lengthier, less-frequent sessions of intense studies. So what's this have to do with Chemistry class? I'm going to tell you:

A little Chemistry each day helps. Your homework usually includes two WebAssigns - one is a "looking ahead" WebAssign in which you read about something that is coming up next. The other is a "looking behind" WebAssign in which you practice using something that we just learned in class. So why not do the "Looking behind" WebAssign on the evening of the Blue day - the day you were presented with the material. And then do the "Looking ahead" WebAssign on the evening of the Gold day - the evening just prior to when we cover the material the next morning. Hopefully that makes sense ... and it gives you a little Chemistry every day.  =SIGH=

Keep Up

Don't fall behind in chemistry at this point. The snowball effect will occur.

That is, you will feel like you're running down a snowy hill with a rolling snowball rolling behind you. The further you go, the bigger the snowball becomes until finally ... .

Hopefully, you get my drift.

Come in and get some help when you need it. Use the referenced web pages and YouTube videso as well. (I highly recommend Tyler DeWitt's YouTube channel.)

    Online Homework


This page changes nearly every day; re-load or refresh to receive the most recent schedule.

Today in Class

>> Friday, December 6 <<

Focus Question(s):
  • How can one use a Lewis Structure and VSEPR to predict the electron pair geometry and the molecular geometry of a molecule?
  • How can the polarity of a molecule be determined from the formula and the Lewis Structure?

  • Any Qs on Lab AMM2?
  • Rdg Guide - Types of Bonds (pp. 23-24)
  • Check-up: Nonpolar .. Polar .. Ionic (p. 22, Q#5-8)
  • To Give, To Take, and To Share (pp. 25-26, Q#1-4)
  • Concept Builder: Ionic Bonding
  • Lewis Electron Dot Structures (pp. 26-28, Q#5-7, selected Qs)


Next Time in Class

>> Tuesday, December 10 <<

We will becomes Masters of Lewis Electron Dot Structures. We will complete pp. 28-30 of the Packet and check our pp. 31-32 Reading Guide. We will earn some Dataways and a homework pass. We will do Lab AMM3 with the help of pp. 33-34. It's a big day.

Periodic Tables

Are you in need of a periodic table?  Try one of the following websites:

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