Matter, Atomic Structure, and Bonding: Bonding

The Lesson 26 PowerPoint introduced students to the four models of chemical bonding.  Students also received a handout of the models with additional information.  After the PowerPoint, students worked in pairs to organize the Substance Cards and recorded their learning on the Lesson 26 worksheet (one per student pair).

Note: worksheet question #8 asked students about elemental substances.  We did not have time at the end of class to explore the topic, so we will discuss briefly tomorrow during class.  Examples of elemental substances are molecular oxygen (O2) and molecular hydrogen (H2), both of which consist of two covalently bound atoms of the same element.  An elemental substances consists of two or more atoms of the same element.

Energy, Matter, and Organization: Why Can’t You Hold Your Breath Forever?

We are giving Google Classroom a try for the first time in Biology class.  After clicking the link, students should enter the class code written on the white board, which will grant them access to the “classroom” automatically in the future.  Once there, students should access the Biology classroom and select the “Why Can’t You Hold Your Breath Forever” assignment.  The assignment consists of four pages of reading from the textbook, followed by a Google Doc worksheet.  After “turning in” the worksheet, the remainder of the class period can be used to review the ocean acidification content linked to yesterday’s post.

Energy, Matter, and Organization: Connecting CO2 and pH with Exercise

We began class with a discussion of of the reading from yesterday.  The discussion focused on helping students understand how to read the questions, how to formulate a response, and the expectation of the quality and depth of thinking expected of a high school student of biology.  Notes from the white boards are pictured below:

After the discussion, students conducted an experiment designed to test the effect of exercise on the amount of carbon dioxide exhaled.  The experiment introduced students to the concept of cellular respiration (vocabulary they will learn soon) by studying the intersection of the cardiovascular and respiratory body systems.  Students measured pH as a surrogate measure of carbon dioxide output by exhaling into a straw placed in a cup of distilled water.  To measure pH, students used probeware connected to hand-held computers.  They measured the pH of the water before and after exercise, writing down their procedure and optimizing the procedure during the class period.  Students obtained data demonstrating a correlation between exhaled carbon dioxide and decreasing pH.

Students wishing to understand the chemistry behind our experiment should visit NOAA’s Ocean Acidification website.  The Smithsonian Institute also has an excellent collection of content explaining ocean acidification that includes some videos about how sea life is affected by increasing carbon dioxide in the atmosphere.

Energy, Matter, and Organization: Stepping Up the Pace

Last week, students were introduced to body systems.  They watched a video showing how the human body reacts under extreme conditions, and then researched body systems involved in the scenarios they saw in the video.  This week, we began with a reading from the class textbook.  The reading introduces students to the concept of homeostasis and feedback loops, while introducing those feedback loops in the context of specific body systems.  Students read page 177, and then pages 229-236, answering questions 2a-d on page 178.  Students finishing early also answered question 3, and then were challenged with searching for the mechanism behind the cycle they wrote about in question 2d.  The directions were also written on the white board and are shown below:

Matter, Atomic Structure, and Bonding: Classifying Substances

We entered the final chapter in Unit 1 with the Lesson 25 PowerPoint introducing students to the concept of classifying substances based on properties of matter like conductivity and solubility.  After slide 6 in the PowerPoint, students received the Lesson 25 Worksheet and then worked in groups of 5-6 students to test the conductivity and solubility of the substances listed on the worksheet.  By the end of class, students had compiled all of the data from the lab into the table on page 2 of the worksheet.  Note: rather than build conductivity testers, students used pre-built testers to obtain conductivity results.

Update – 11/17/15: We compiled a class data set from yesterday’s conductivity and solubility tests.  A few of the substances had mixed conductivity results across student groups, so we re-tested the conductivity of those substances using a conductivity tester constructed as instructed on page 1 of the Lesson 25 worksheet.

Energy, Matter, and Organization: How Humans Obtain Energy – Initial Model

Our work today is to organize student prior knowledge of how humans obtain energy into a model that can be revised over the course of the unit.  Recent learning from the Strength video and worksheet from Monday should be used to help students fill out the initial model worksheet.  The worksheet must be turned in at the end of class, so students should work efficiently to:

  1. Select one of the four scenarios from the video
  2. Review that scenario by watching that segment of the video (see Monday’s post for a link to the video)
  3. Draw and label the body systems involved (including the major organs of the body systems) on the worksheet
  4. Explain how the person in the scenario both gets and uses the energy and matter needed to survive in the scenario.
  5. Complete the three questions on the back of the worksheet, answering as completely as possible.
  6. Turn in the worksheet at the end of class for credit.

For a review of body systems, visit the website InnerBody.com and watch the Crash Course body systems videos to learn more about body systems relevant to the selected scenario.

Matter, Atomic Structure, and Bonding: Electron Configurations

Note for November 12: Students, please scroll down for additional resources/instruction!

Our learning about electrons culminated today with Lesson 24, in which students understanding of electron shells was expanded to include the concept of subshells.  We worked through the first 10 slides of the Lesson 24 PowerPoint, and students also received a copy of the Lesson 24 Worksheet.  Students used the last part of class to read through Lesson 24 in the textbook and begin working on the worksheet.

To help students build a better foundation as they learn the challenging concept of electron subshells, students are encouraged to watch the Crash Course chemistry video below:

Want more?  There is a follow-up Crash Course video (#25) that picks up where this one left off and takes the content to a whole new shell (sorry, chemistry humor):

Note: No school on Wednesday, November 11 (Veteran’s Day)

Additional content for Thursday, November 12 is being posted in advance to serve as reference material for interested students:

There are two handouts on the front table – one is a new copy of the Periodic Table that includes electron configurations.  The other is an outline of the Period Table with electron subshell blocks.  Feel free to take one of each to use as a study tool.  By now, everyone should have read through Lesson 24 in the textbook.  To supplement your learning, I have drawn out an electron subshell filling tool on the left white board (pictured below).  By following the orange arrows while moving own the rows, you can see that the electrons fill subshells in a specific way.  Remember, the s orbital only has room for 2 electrons, the p orbital has room for 6, the d orbital holds up to 10 electrons, and the f orbital has room for 14 electrons.  Following the arrows, you can see that subshell 1s fills first, followed by 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d and so on.  The number written in superscript to the right of the subshell indicates how many electrons are in that particular subshell.  The electron configurations for hydrogen, helium, and carbon are written and drawn out on the left white board.

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The electron configuration for bromine is written out on the right white board (above), along with the question: how many valence electrons does bromine have?  You should be able to determine by looking at the Periodic Table that bromine (Br, element number 35) has 7 valence electrons.  The question to consider is: how might the electron configuration be used to determine that? The video below will explain that, and will provide you with several practice questions (and answers – pause the video and work through a few of the problems!):

Students looking for a deeper dive into the content, including the advanced concept of electron spin (not something you will be tested on, but I know many of you are bound for college chemistry…), are encouraged to watch the Bozeman Science video below:

We will review Chapter 4 on Friday in preparation for the Chapter 4 Quiz on Monday.