VIDEO: MODELING THE ATOM, PART 2 (ATOMIC MASSES)

STUDENTS:

This VIDEO has a broad discussion of the role of mass in our models of the atom:  protons, neutrons, atomic mass units, mass numbers, isotopes, the negligibiliy of the electron's mass and mass weighting problems.

It also points out the interesting fact that both the periodic table and the metric system have been "tinkered" with so that the numbers in the periodic table can be interpreted either in terms of amu (atomic masses) or grams per mole (molar masses) . . . very clever, and very useful:

VIDEO: BRIGHT LINE SPECTRUM CALCULATIONS

In this VIDEO, Mr. Hatfield models calculations that allow students to determine the frequency and the energy of a particular light wave seen in spectroscopy, as discussed in Section 4.2 of our text.

BUT JUST AS IMPORTANT, Mr. Hatfield models the use of a notation for displaying very large or small numbers that mimics with the 'EE' key found on many scientific calculators. This is a SUPERIOR method that saves time, reduces the likelihood of student error and has students writing out these numbers in a form that matches the way they enter those numbers into a calculator!

And, since students will be using that method for the rest of the course, it is important that students master the use of that method for future success.

FIRST BIG TEST!

Your first major exam in this course will occur on Monday and Tuesday (Oct. 19th and 20th):

It will include calculations on velocity, acceleration, force, energy, and the wavelength and frequency of light waves, using the following equations:

It will include material that appears in Sections 4.1 and 4.2 of your text (pg. 100-115), plus previously-covered material

You may see diagrams of atomic structure as taught by Mr. Hatfield in class, that look like this.  Know how to interpret them:

You will need to know the following numbers:

The speed of light (c), is:

Planck's constant (h), is:

Take this seriously.  No one will be able to finish this exam in 20-25 minutes.  It may take students the entire period, and they may need extra time outside of class to finish that day.

BE PREPARED.

GRADING ISSUES ARE A GRIND!

Students:  Your instructor is making a good-faith effort to get 'caught up' on grading, and overcoming the recent ATLAS outage from last Friday.

But I need some of you to do some things:

1)  First, if you think there is a mistake in your grade, or missing grades, please contact me personally via email or private chat.  I'm having students put questions about their grades broadcasting them in class or during Student Support, when other students are present.  I need to discourage that!   You have a right to expect a level of privacy where your grades are concerned.

2)   If you need help about things other than grading questions, then by all means come to STUDENT SUPPORT when it is offered.  (Please note that it will not be available on Thursday, 9/15 this week).  If you are unable to attend, but need support, you should approach me privately about arranging for one-on-one tutorial time outside of regular class hours.

3)  Finally, please DON'T submit completed work to Microsoft Teams!  I've actually made this request many times in all my classes, and some of you continue to do it, making EXTRA WORK for me.  Some of you do this, even when the Assignment instructions tell you otherwise.   For example, there is a whole group of kids who keep telling me I haven't entered their 'Balanced Equations Study Guide' grade, whose actual instructions read as follows:

I don't use Teams for several reasons, but a very important one is this: it sometimes thinks you've turned in work, when you've actually failed to attach any work: 

I don't trust it to handle your important work.  Please instead send it to me in an email, addressed to: scott.hatfield@fresnounified.org

VIDEO: MODELING THE ATOM, PART 1 (ATOMIC MODELS AND LIGHT)

This VIDEO is based on section 4.1 and 4.2 of the text used by Mr. Hatfield's students. It rreviews the 'building blocks' (protons, electrons and neutrons) that make up atomic structure in current models:

The video then challenges students to understand the experimental evidence justifying these subatomic particles with famous experiments, like the electrolysis of water, Rutherford's gold foil experiment and the Bohr model which provides an explanation for atomic emission spectra.

The goal of this approach is that students develop an understanding of how models of the atom evolved in response to new scientific findings. Unlike ancient philosophers, who merely attempted to persuade others that their ideas were appealing, scientists must always subject their ideas (no matter how clever, beautiful or beloved) to the 'test of nature': experiment!

VIDEO: BRIGHT LINE SIMULATION

 In this VIDEO, your instructor  demonstrates the use of a PHET simulation, which is available HERE:

This simulation models the production of spectral lines by excited atoms of various elements.

Your instructor then shows how to represent data collected from this activity in a Word document, data that will be used to derive the frequency of the spectra and (by Planck's constant) the energy of the photons associated with that frequency.

VIDEO: INTRODUCTION TO ENERGY (CALCULATIONS)

In this VIDEO, Mr. Hatfield has rearranged material from the opening chapters of the district's new chemistry text, in order to bring more of the background information about SI units and calculations together in one sitting.

You can watch the video by clicking on the link above or within this post.

A particular assignment based on this video will be shared with all students through email and as an Assignment, through their class period's channel in Microsoft Teams.