Earth History Timeline

Now that students better understand how scientists use radiometric dating to determine the age of physical items and structures, it is time to look into the deep history of Earth.  Students should research the following events, determine when they occurred, and construct a timeline of the events:

  • First dinosaurs
  • Formation of Mount Rainier
  • First hominids
  • Break up of Pangea
  • First vertebrates
  • First life (bacteria)
  • First modern humans
  • First oxygen in the atmosphere
  • First land plants
  • First animals

On Friday, we made a timeline of the last billion years of Earth history on the football field:

1st Period Timeline
4th Period Timeline
6th Period Timeline

After we debriefed the timeline exercise back in the classroom, if time permitted, students watched one of the two videos below:

There’s Mounting Evidence The African Continent Is Splitting in Two

Homework Review

Before we dive too deeply into pH, we take today to brush up on unit conversion and scientific notation using the Unit Conversions 2 – Scientific Notation and Significant Digits Gizmo.  Students who needed additional time and/or help with homework had the opportunity to work in small groups and with the teacher.  At the end of class, students who want the opportunity to re-take the chapter 15 quiz received the Chapter 15 Quiz Retake Ticket as homework.  The packet requires students to show their work as they solve problems and the packet must be completed correctly before students may retake the quizStudents who want to retake the Chapter 15 quiz must do so after school on Monday, April 2.

Acid and Base Theory

We extended our learning about acids and bases by learning and applying the Arrhenius and Bronsted-Lowry definitions via the Lesson 85 PowerPoint, the Lesson 85 worksheet, and the Acid-Base Solution Card sort activity.  For homework, students were assigned textbook problems #1-8 from Lesson 85.

Students who would like to further their understanding of Bronsted-Lowry acids and bases are encouraged to watch the Khan Academy video provided below:

Radiometric Dating

Last week, we learned about Darwin’s voyage and how he collected data to formulate his theory of evolution.  We went on to study biological classification, using the system devised by Linneaus way back in 1735.  Previously, we learned that scientists collecting were able to date common ancestors of humans to over 3 million years ago.  Our work over the next few days will be to learn how scientists use radiometric dating to estimate the age of really old samples.  We will begin an introduction to chemistry, focusing our efforts on understanding the difference between carbon-12 and carbon-14 atoms.  Class notes are pictured below:

Next, we will watch a video introducing radiocarbon dating:

After the video, we will begin the Radioisotopes Activity.  We will read through the first few pages, and then tomorrow students will work with a partner to complete the activity which is anticipated to wrap up by Wednesday.

Acids and Bases

For the first lesson of chapter 16, students were formally introduced to acids and bases via a lab.  We began class with the Lesson 84 PowerPoint which included a starter question helping students connect acid/base chemistry with the biology of heartburn.  After learning about indicators, chemical solutions that change color in response to changes in pH, we reviewed the Lesson 84 worksheet.  For Part 1, students were instructed to number the nine solutions in order, with the number on the worksheet corresponding to one of nine numbered flasks containing the indicated solution. An image of the lab setup is shown below:

After students complete the lab portion of Part 1, they were instructed to return to their seats to complete the Part 1 analysis questions.  We will share out results as a class, and if time permits, conduct Part 2 as a teacher-led demonstration.

Universal Indicator Chart
Universal Indicator Chart


Red cabbage indicator chart
Red cabbage indicator chart

Example of student results with indicators – samples are arranged #1-9 in rows A and B, with cabbage juice indicator in row A and universal indicator in row B.

Part 1 Student Results

Results from the teacher-led demonstration for Part 2 are shown below:

Acidic solutions reacted with the calcium carbonate antacid tablets (Tums).

Biological Classification POGIL

We continued our investigation into the history of biological research by moving past Charles Darwin and learning about the work of Carolus Linneaus, the father of modern taxonomy.  To help place the concept of taxonomy into historical perspective, we took a few notes connecting the discovery of the structure of DNA, the publication of Darwin’s work on evolution, and the publication of Linneaus’ work on taxonomy.  Class notes are shown below:

  • Structure of DNA discovered in 1953
    • James Watson (1928- )
    • Francis Crick (1916-2004)
    • Rosalind Franklin (1920-1958)
  • Theory of Evolution, The Origin of Species (published 1859)
    • Charles Darwin (1809-1882)
  • Biological Classification / Taxonomy (Systema Naturae, published 1735)
    • Carolus Linneaus (1707-1778)

After the notes, students each received a copy of the Biological Classification POGIL and we worked through the first two pages together as a class.  Students who would like additional learning about taxonomy are encouraged to watch the Crash Course video below:

Students who complete the POGIL activity early are encouraged to assemble and share with me a Google Slides consisting of organisms from as many different diverse species as possible.  Each slide should include a picture of the organism, it’s common name, and the complete taxonomic naming (from Kingdom through Species).

On Friday, we will review the POGIL and work through the final problem of the (question 23) as a class. For the last few minutes of class, we will review slides 5-8 of a PowerPoint describing complex relationships between organisms.

Students are encouraged to watch a National Geographic video about zombie parasites this weekend.  The presenter, Anand Varma, applies his expertise in photography to the study of parasites.  Mr. Varma travels the world collecting specimen for study, and his ability to apply biological concepts to his work, think creatively, and drive to overcome failure make him and his work truly remarkable.

Darwin’s Voyage

Despite the disruption of multiple fires started by students in the restrooms, we managed to take class notes on the four key facets of evolution studied thus far (pictured below).  A few classes were able to begin the activity below the picture.

A part of Darwin’s journey to developing the idea of evolution was in the Galapagos Islands.  You will start by taking a tour of where he went and what he observed.  Go to Explore the Galapagos on the PBS NOVA website and go through the interactive tour.  Answer the following questions in full sentences below in your lab notebook and turn in for credit:

  1. Where are the Galapagos Islands?
  2. First click on “Explore the Islands” and read about three of the islands.  Summarize one observation for each of the three islands you read about.
  3. Look at “Darwin’s Finches”.  What do you think it means by unique niche, based on what the rest of the paragraph says?
  4. How are the beaks different and why was that important?
  5. Now click on “What Darwin Saw”.  You will be going through his various stages and reading about what Darwin said (if you have headphones you can listen to the interviews as well).  Summarize Darwin’s first impressions (just writing the opening sentence will get you zero credit, click for the full story).
  6. What surprised Darwin on the islands?
  7. What did the tortoises offer the local people?  How did it benefit Darwin?
  8. At first Darwin thought the birds were unrelated, but what ideas eventually came from his observations of the finches?
  9. What was the fallout (or result) of Darwin’s journey?
  10. Go back to the “Explore the Islands”.  Look at some of the interpretative panoramics and the animals.  Pick one (or two for a bonus point) animals and summarize their unique characteristics.

Mystery Solutions

We began class today with the entry task from the Lesson 83 PowerPoint.  The student-driven solution is provided below:

For the remainder of class, students worked through the Lesson 83 Worksheet.  We began with Part A, in which students were tasked with determining which mystery solution matched with one of three chemical formulas.  The mystery solutions each had a different mass, but all three were known to be 100 mL and 1.0 M solutions.  Notes from the white board are provided below.  For homework, students were assigned problems #1-8 from Lesson 83 in the textbook.  Also, students were provided with a printed copy of the Chapter 15 Study Guide and were told about the revised schedule for next week (Chapter 15 quiz on Thursday).