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Posts Tagged ‘Science’

Goal: Be able to use the law of conservation of mass to write balanced chemical equations, identify the basic types of chemical reactions, and predict the possible products from a given set of reactants.

You must demonstrate your achievement of this goal.  In a blog post, (1) explain how to balance an equation and why it is important, and (2) describe different labs you did, what type of reaction it was, and provide a balanced reaction for each.  You have done synthesis, decomposition, single-replacement, and double-displacement labs.

You must also (3) describe how to predict the possible products that will occur from a given set of reactants, and (4) demonstrate your ability to predict reaction products.

As of the first week of March, chemistry students have conducted the below list of chemistry labs. Use this list to support your evidence of attainment of the above goal.

  1. Baking Soda to Salt Lab
  2. Limiting Reactants Lab
  3. Chemical Reactions Webquest
  4. Three Types of Chemical Reactions
  5. Reactivity of Metals
  6. Hydrate Lab
  7. Molecules of Candle Burned
  8. Molecules of Chalk In Your Name
  9. Covalent or Ionic Bonding Lab
  10. Halides Lab
  11. Periodic Trends
  12. Ionic vs Covalent
  13. Half life of Candium
  14. Isotopes of Vegium Lab
  15. Rutherford Lab
  16. Law of Conservation of Mass
  17. The quality of Laboratory Measurements
  18. Measuring Stuff: Tools and Skills
  19. Density Problems
  20. Lab Skills Lab
  21. Observations Lab
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This past month chemistry students have been learning how to convert between grams, molecules, and moles, so each day the bell-ringer/do-now/QOD assignment was a calculation of molecules of something familiar: chalk, candle wax burned, nicotine, aluminum foil, etc. I believe that each day’s practice helped solidify their understanding of the concept. So one day I asked how many molecules in a snow flake. Since we had to start with a mass, and I did not have time to determine the mass of a single snowflake, I turned to the internet and found Archimedes Notebook: How much does a snowflake weigh?  Thus, I gave the students the following information

Most snowflakes weigh from 0.001 to 0.003 grams, with a heavy snowflake coming in at 0.02 grams. Choose a mass within that range and calculate the number of molecules of water in the snowflake.

Thus, different students came up with different numbers of molecules, giving us a range of data.  Note:

The largest snowflake ever seen was 8 by 12 inches and was reported to have fallen in Bratsk, Siberia in 1971.

Most students elected to use the average of the lower two numbers, and calculated as follows:

mol snowflake

That is a lot of molecules. Adding or subtracting just one molecule of water would result in a unique snowflake. And considering that water is a polar molecule, the hydrogen bonding arrangement possibilities is mind boggling.

Then we have to consider factors that affect how a snowflake develops. NOAA gives this simplified explanation, which still is not the entire story:

A snowflake begins to form when an extremely cold water droplet freezes onto a pollen or dust particle in the sky. This creates an ice crystal. As the ice crystal falls to the ground, water vapor freezes onto the primary crystal, building new crystals – the six arms of the snowflake.

…The intricate shape of a single arm of the snowflake is determined by the atmospheric conditions experienced by entire ice crystal as it falls. A crystal might begin to grow arms in one manner, and then minutes or even seconds later, slight changes in the surrounding temperature or humidity causes the crystal to grow in another way.  ~ NOAA

From snowcrystals.com we get a bit more information:

Snowflake Morphology

Snowflake Morphology

We see that thin plates and stars grow around -2 C (28 F), while columns and slender needles appear near -5 C (23 F). Plates and stars again form near -15 C (5 F), and a combination of plates and columns are made around -30 C (-22 F).  Furthermore, we see from the diagram that snow crystals tend to form simpler shapes when the humidity (supersaturation) is low, while more complex shapes at higher humidities. The most extreme shapes — long needles around -5 C and large, thin plates around -15 C — form when the humidity is especially high.

PBS tried to get a definitive answer to this question “So is it really true that no two snowflakes are alike?” from physicists Kenneth Libbrecht, a physics professor at the California Institute of Technology and avid snowflake photographer, and John Hallett, director of the Ice Physics Laboratory at the Desert Research Institute in Reno, Nev., and got the following response:

“It’s like shuffling a deck and getting the exact same shuffle for 52 cards,” Libbrecht said. “You could shuffle every second for the entire life of the universe, and you wouldn’t come close to getting two of the same.”

So, there you have it. While not impossible, it is highly unlikely given that there are a trillion, trillion, trillion (a 1 with 36 zeros!) different types of snowflakes.

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Portion of ocean floor, from Google Earth

Portion of ocean floor, from Google Earth

Research Questions

How can ocean floor features be measured and mapped using current acoustical technology? How can ocean floor maps be used in the commercial, military, and/or private sector?

Objectives

  • Use the description of ocean floor features to construct a three-dimensional model of a section of the seafloor.
  • Simulate active sonar soundings of a model of the ocean floor.
  • Describe the concept of vertical exaggeration and why it is used in construction of side profile maps.

Procedure

In class, we created models of portions of the ocean floor, using playdough, and simulated collecting sounding data in a grid format.

Analysis

  1. Based on your seafloor model provide a description of the topography of your surveyed area.
  2. Using the sonar stick is actually simulating what is known as remote sensing technology. What are the advantages of using remote sensing technology for your survey instead of direct observation?
  3. When graphing the ocean floor features we stretched the Y-axis. This is known as vertical exaggeration. What is the advantage of using vertical exaggeration in constructing your profiles of the seafloor?

Conclude and Communicate

  1. Identify the research questions for this activity, and your ideas/answers to those questions.
  2. Define the following ocean floor features (your model maps contained at least three of them) and provide pictures for three of them:
    1. A flat abyssal plain.
    2. An underwater seamount or guyot.
    3. A continental shelf, break, slope, and rise.
    4. A submarine canyon on the continental shelf.
    5. The mid-ocean ridge.
    6. A trench and island arc system.
  3. Write up responses to the three analysis questions above.
  4. Write two new research questions based on what you have learned from this activity:
  5. What was the value and importance of this activity to your study of science.

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You have been challenged to design a practical underwater laboratory, or habitat, for aquanauts to live and work  for one to two weeks while they conduct marine science research. The considerations you’ve been ask to account for in your design are:

Image

One thing that you are not taking into consideration is the practicality of building your aquapod and assembling it underwater.

A network of focused experimental sites are being constructed in the Northeast Pacific Ocean to serve researchers, students, educators, and policymakers and begin “a new era of scientific discovery and understanding of the oceans”. The research stations are not habitats for living in but rather a series of sites with an array of monitoring equipment for monitoring chemical, physical, biological, and sediment conditions.

Your task today is to:

  1. Read the news article describing the observatory.
  2. Watch two or three three short videos of the work being undertaken. I suggest Dive 1482 Highlights, Dive 1604, and Dive 1596 Highlights.
  3. Read the National Geographic article Huge Molasses Spill Off Hawaii: A Diver’s Report.
  4. Write a two to three paragraph blog post that reflects either:  a) your thoughts on the observatory installation (How tricky is it to build an underwater research station? What considerations must be accounted for?); or b) your thoughts on the effects of the molasses spill (How should people respond to this? Could this have been prepared for? What should be done next?).

That’s it: two to three paragraph blog post on one of the above topics (but read both). Make sure you label your post, include cited pictures, and include at least two hyperlinks to further information.

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Seeing Sands From Different Seas

This particular sand viewed through a microscope is from Maine. As observed, its got different colors throughout every fragment, browns, greens, whites, blues, mostly dark colors though. This sand was not magnetic, and has a size of about 1 millimeter. Our class determined that the sand can be classified as angular, moderately sorted, and composed of different rocks and possible debris.

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Our trip to the OdiorneBeach   Theresa Apicella

Yesterday, October 4th we went on a field trip to the NationalSeacoastScienceCenter in New Hampshire. We got to learn about the sea creatures that live in the small bodies of water. I learned that certain animals can only live in waters that are a certain temperature. When we checked out the touch tank, the water was freezing because the animals in there can only survive in that temperature. When we were outside we got to actually go in the water and look for animals. We found lobsters, crabs, snails, and sea urchins. It was a lot of fun to be able to find all these animals and learn about them. When we were inside we learned about the change of the water temperature over the seasons and how everything changes underwater when the seasons change. I really enjoyed visiting the science center and being able to discover all these new things and learn so much.

The Beach Area                                                                Some Lobster from the OdiorneBeach Water

http://www.seacoastsciencecenter.org/

http://www.youtube.com/watch?v=uzFEdsmub0U

http://www.seacoastsciencecenter.org/visit_today/odiorne_point.php

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