Saturday, October 4, 2014

Amazing Water Trick

Short, Beautiful Chemistry Videos

5 Precipitation Reactions at various speeds.

This video shows the color change of purple cabbage and a flower named Teornia fournieri in sodium hydroxide and hydrochloric acid solutions.

The displacement of metals at various speeds.


Credit: Institute of Advanced Technology, University of Science and Technology of China (BeautifulChemistry.net)

Sunday, August 24, 2014

Dimensional Analysis: Start with what the students know

Want your students, especially those that struggle in math, to be successful in dimensional analysis all year long? In that case, I highly recommend that chemistry teachers start off using units that are relevant to students, as well as incorporating dimensional analysis on a continual basis (more on the latter later). When I first started teaching chemistry I began the dimensional analysis (DA) unit with metric problems. The challenge here in the USA is that we don't use the metric system like other countries do and so not only was I facing a battle teaching DA, I was also battling student knowledge concerning the metric system. I was frustrated. The students were frustrated. It was a lose-lose situation. 

I decided to change my approach my second year of teaching based on what I believed most, if not all, students would be familiar with - money. My students were grouped in fours and each group received a bag of coins...yes, actual coins and I always received the exact amount back. 
Of course this could be done with fake money or without it as well; however, I wanted my students interacting with objects and discussing - so decide fake or real $$$ if you wish to do this. I would start off by asking the students to make me a dollar out of each set of coins. They all knew how to do this (100 pennies, 20 nickels, 10 dimes, 4 quarters).
I would then choose a set of coins (for example, quarters and dimes or nickels and pennies) and ask the students to discuss in their groups for approximately 30 seconds to 1 minute if these measured the same quantity. Group answers were always yes.  Then I would ask students to try to write a mathematical relationship to show this. 
Most groups would write 4 quarters = 10 dimes or 20 nickels = 100 pennies. I would then write the equality as a fraction on the board (both ways as shown in the two graphics above) and ask the students to discuss in their groups for approximately 30 seconds to 1 minute if both fractions were the same. As I walked around I would hear some groups agreeing and others disagreeing. I would then pull the class back and use Popsicle sticks to call random students to share (either they could share what they believed or if they were not confident in their response they could share what their group discussed). After a few student responses, I would talk about conversion factors and equalities (still using the illustrations shown above). I would ask students to write a conversion factor for $1 using dimes and nickels just to ensure they were understanding and following along. 

Next, I would move to another topic students were familiar with - time. I don't know about you, but students are always asking for the time or when class is over or when something is beginning; it's probably the reason I didn't have a classroom clock. Anyway, to see if students understood the money concept, I would ask them to write a conversion factor for 1 hour and 60 minutes (shown below). 
Other years I've written the conversion factors on the board and asked if the fractions were the same. I would challenge groups to come up with as many time conversion factors as possible within a 1-2 minute period (examples:  24 hours = 1 day;  365 days = 1 year;  10 years = 1 decade). After this, I would move into the heart of dimensional analysis (DA). My main focus was ensuring that students understood and could show the steps of the process. Even if they calculated the answer incorrectly but set up the problem correctly that was okay (at least for now as that was a technical issue). 
I had a magnetic white board and printed out colored pieces similar to the illustration above and used magnetic tape (you can use different colored paper versus color ink). I would then tell the students: Criss-cross apple sauce. At this point I would get laughed at and also felt a little silly no matter how many times I had said this in the past; however, it was an instructional tool I used throughout the lesson. I would mention criss-cross apple sauce and ask students to look at the magnetic pieces on the board (shown above).  Of course, I purposely mixed some of the units around to show students the idea of canceling units that were similar in the numerator and denominator as it does not matter mathematically where they are at in the problem. However, if you think that might confuse them, then put the units in order from given to unit wanted
At this stage of the game I would incorporate the Gradual Release model (I do, We do, You do) and work a few problems making sure I said Criss-cross apple sauce as often as possible while working problems. I should note that I had large student white boards and each student practiced on them during this part of instruction. Additionally, for each problem, I would give students the conversion factors (example shown above) and stress that they could only use a conversion factor once and to cross it out when they did. I would stress this because sometimes students would use the same conversion factor twice in the problem (written in both forms - see examples at top for reference). Some teachers might be against this, however, my goal is to build comprehension and capacity for solving these problems. In the beginning I want students to show me they understand the concept/skill of dimensional analysis, not whether they can memorize a bunch of conversion factors - at least that is not the standard here in Texas and probably not the standard in many places.


Last but not least, is how I grade student work. As we practice (during instruction or a warm-up), I go over the points system and show students how they earn points per problem. This problem is worth six points: 1pt. per conversion factor step, 1pt. for the correct answer, 1pt. for the answer written with the correct number of significant figures, and 1pt. for the unit. By the time students take a quiz or test they realize the importance of showing their work and it usually is not a hassle. 

I continually incorporate DA warm-ups and tricks throughout the fall semester so students have had plenty of practice by the time stoichiometry comes around.  I like to be evil during labs and tell students to weigh out a unit of a substance not in grams (for example 50mg of sucrose) and quietly laugh as students go back and start weighing. Some groups will realize right away that the balances only measure in grams, while others will not; but it's a great way to incorporate DA throughout the school year.  :p

Whew! That was a lot. I hope this helps. I would be remiss if I didn't highlight a few of my products geared toward this topic.  The first one is a Dimensional Analysis: Time Conversions Cut & Paste activity for the Interactive Notebook.  The other is a bundle of items for a measurement unit - Numbers in Science for the Chemistry Interactive Notebook and has a metric cut & paste activity, as well as dimensional analysis notes and problems. Check out the reviews and if you have any questions, feel free to comment here or leave a message at Bond with James: Q&A (click on the tab)























Friday, August 22, 2014

Bins, bins, bins!

Group bins (or totes) have been a life saver over the course of my career as an educator. Not only do the bins keep me organized, it makes it so much easier for students to access materials. Additionally, I've used this same technique for professional development sessions across my district and at conferences.


One thing that I've done to make it easier to transport a large number of bins is to purchase a larger tote to place the smaller versions into.  I'm sure there is a large tote with an expanding handle and wheels similar to luggage, however, I didn't spend too much time looking for that version. 




I place the same items in all the bins (although these need to be updated this school year):

  • 1 box of Crayola markers 
  • 1 box of Expo markers (for whiteboard activities)
  • 2-4 Sharpies 
  • 2-4 boxes of Crayons 
  • 4 Glue sticks 
  • 4 Tape dispensers
  • 4 Post-It pads (two 3"x3" pads, two 5"x8" pads)
  • 4 Scissors (I just completed a staff development and used adult scissors. I use kid scissors when working with students). 
  • I'm thinking about adding color pencils.
Each group gets a bin and all four students have access to the materials.




This is a classroom I recently conducted a professional development session in. However, the setup would be identical to my classroom (although, I had lab tables). The only time students really need to get up is to sharpen their pencils or throw away trash; or if we are moving based on an instructional activity. However, I purchased cheap bins from the dollar store and placed one at each group table to make trash disposal easier. Boxes and the group area were checked for cleanliness as a dismissal method (to save me from cleaning the boxes and the janitors from having to sweep all the trash off the floor). Additionally, I had two electronic sharpeners on both sides of my room to make sharpening pencils readily accessible for students. 



If you use interactive notebooks in your class then I recommend a system similar to what I have shared here. Your life (and the lives of your students) will be so much easier as they will have all the materials at their disposal versus a bunch of students getting up to grab random materials.

I purchased the bins online at Office Depot as my district receives a discount. Check with your campus and/or district to see if they receive discounts at office supply stores. Here is the product info in case you're curious:
  • Really Useful Boxes® Plastic Storage Box, 64 Liters, 12 1/4"H x 17 5/16"W x 28"D, Clear​   Item # 787653    
  • Really Useful Boxes® Plastic Storage Box, 4 Liters, 3 1/4"H x 10 1/4"W x 14  1/2"D, Blue Item # 546858  ​
I believe there are 4 liter transparent boxes. You could even organize the boxes by coloring or placing some other different identifier on each box. I just numbered the materials inside the box to correspond with the number written on the outside. Be as creative as you wish. :)

Saturday, July 19, 2014

Classroom Organization Tip


I used to do a lot of group activities in my classroom (2-4 students per group). I had 8 student groups in my old classroom and this meant creating 8 sets of a single activity (or sometimes 16 sets if I wanted a group of four to split into pairs).  I didn't mind creating all the sets because the management of smaller groups was easier than working with a large group. However, at the end of the school day, no matter how hard I worked to get the students to keep their sets separated, there was always a set or two with extra cards. I would waste precious nap (or grading) time going through all the sets. I realized I needed a method to quickly identify mixed sets.

What I am sharing with you is cheap and easy. There are multiple ways you can tag your sets to quickly identify them. Keep in mind that you should tag your cards with an identifier prior to lamination (if you like to laminate). This will ensure that the identifier is sealed...well, of course, if students don't tear the lamination off. 

I used the circular stickers for this tutorial. You can find them at most office supply stores or even your local grocery store.  

For each set, place a sticker (or use a marker to draw shapes or lines) on the back of each card. Do this prior to lamination. Below you can see that I placed 4 pink stickers on the back of each card of one of the sets. Additionally, I am also showing how you could use a marker to scribble, color, or draw on the back of each card instead (especially if you don't want to spend money on buying stickers). 


Remember, you will need to use a different color sticker or other identifier (e.g. marker) per set. Laminate once you have placed different identifiers on each set. 
 Chemical Reactions Task Cards



The picture below shows that I have 8 sets (of the same activity) - all with a different identifier. Note: I just used one card from each set to show this in the picture.

Finally, place each set of cards in a baggie or container. I prefer to use Ziploc baggies because they  are cheap and last a long time. Additionally, you can stuff a bunch of card activities into a drawer or closet.  If using stickers, I also recommend placing a matching sticker on the bag. This will help students catch cards that don't belong to a set (especially if you ask students to conduct a quick check prior to return). For example, only cards labeled with a blue sticker should be placed into the blue baggie and so forth. Of course, you could buy colored baggies to be even more organized; however, this should work if you're on a budget. 

         

I hope this helps keep your cards/activities a bit more organized. This tip will come in handy if you utilize task cards in your classroom. 



Friday, April 18, 2014

Model a Chemical Reaction with Common LEGO® Bricks!

Another 2014 NSTA experience...
This session was geared toward the middle school level; however, I was curious to see what I could possibly learn and bring back to teachers in my district. The first activity involved the following materials and chemicals per 2-4 students: Ziploc bag, baking soda, calcium chloride, phenol red, water, and plastic vial or test tube. The presenters had us put a teaspoon of baking soda followed by two teaspoons of calcium chloride in a bag. Participants were instructed to place a vial (or test tube) with approximately 10mL of phenol red solution into the bag and hold it upright (this vial came with a cap). We were then instructed to leave the bag upright, remove the cap, and remove the remaining air inside the bag. Finally, we were instructed to tip the phenol red solution onto the solid mixture and mix it from outside the bag with our fingers. 

As always, here is a video for you demonstrating what I discussed above...

There were two other sections (I have not included pics since I've done this countless times with my students). The first allowed students to design two more experiments in order to determine which reactants would produce a color change, gas, and/or heat. Session facilitators handed baggies with different labels. Here is a rough sketch of what this part of the worksheet looked like; this is just to give you an idea.
The second section of the activity was a class activity where students and teacher worked together to determine which substances, when mixed, produced a color change, gas, and/or heat; and this was completed on a worksheet. 

On a side note, there was a participant at my table that clearly did not believe that this activity was suitable for middle school students; however, the rest of us were in agreement that this was an activity that was appropriate for the indicated grade level. Her comment baffled me and left me wondering if that was the reason why many of my students come to me with limited chemistry / wet lab experience because they had a teacher who didn't (1) believe in them and/or (2) challenge them with scientific experiences.

Anyway, the second half of the session involved playing with LEGOs®. 

I won't bore you with all the extraneous details; however, the basic concept of this activity was to help students write formulas and develop an understanding between elements and compounds. 


 If the set interests you, here is the link to a PDF flyer where you can learn more about the number of sets, costs, etc.  If you have/had children, you might just borrow from them or take a stroll to the nearest store to see if you can purchase LEGOs® for a much cheaper price.
Atoms and Molecules Set Info
Rationale for Using LEGO Bricks as Atoms


Thursday, April 17, 2014

Engaging Students in Mitosis and Meiosis

I had the opportunity to attend the 2014 National Science Teachers Association (NSTA) conference in Boston. I am behind in recapping my experience and therefore, I am going to select certain sessions to discuss/share - the first session I'm sharing is covers mitosis and meiosis. Sorry the pictures are arranged weird. I was experiencing issues with the site and just gave up after a while.

The presenters (Mary A. Gobbett and Nancy O. Steffel) shared their stations for engaging students in learning / reviewing mitosis and meiosis. I believe Mary mentioned that the activities were created for and by college students; however, the activities can be used for students in a high school level biology class. The presenters spent 20-30 minutes going through each station (pictured below) and then provided participants the opportunity to go through the stations during the remaining time. 

Station 1: Popbeads
This station consisted of popbeads which I believe you can purchase from Wards, Sargent-Welch, or other science companies. The idea behind this station was for students to experience a chromosome simulation via manipulation of the popbeads (since you can take them apart and connect them together however you wish). The students are able to illustrate the stages of mitosis and meiosis. 
 

Wondering what this looks like? Paul Anderson (Bozeman Science) demos that in the video below. Yes, I was able to get a picture with him at NSTA this year; however, I'm not one for posting horrible pictures of myself haha.

Station 2: Root Tip Slide Photos
I've seen and used a station like this before. I believe the presenters ordered a set from one of the science companies (Wards, Flinn, Caroline, etc.); however, they also mentioned that you could find images on the Internet - provided that you give proper credit, of course. The one thing that the presenters talked about that I liked was the fact that students used their phones to take pictures of the slides through the microscope. I thought that was a neat way to incorporate technology and cell phones, especially when that phones tend to be a hurdle for educators. Students use the pictures to identify the different stages of mitosis shown in each picture (as well as quantify the different stages).
 

Station 3: Cell Cycle Plates (Eukaryotic Cell Cycle)
The presenters used large pieces of filter paper to create the cell cycle plates. However, you could create these out of paper plates. There really wasn't much else to this station. I'm sure a teacher could have questions or scenarios for students to complete while they are at this particular station. 


Station 4: Playing Cards
The presenters used small cards, magnetic tape, and a magnetic cookie/baking sheet. However, take a look at the YouTube video (click the link) to get an idea of what this station is about (lower your volume if you have headphones on).


Station 5: Sister/Homologous Chromatids/Chromosomes
To be honest, I forgot exactly what this station was about. I think it was to help students develop an understanding of the vocabulary by presenting multiple visuals. I will have to email the presenters to find out. The presenters used pool noodles (top picture)  and dyed packing peanuts (bottom picture).

Stations 6 & 7: Human Chromosome Genome Map Sheets
I believe this set had to be purchased from a science company (VMR - search for the title of this station). I think she used this station as a means of helping students determine the genotype/phenotype given the maternal and paternal alleles for over a dozen traits. There were several pages that went along with this activity; however, I am not able to post them here - sorry.

Mitosis and Meiosis Dance
The name says it all. The presenter had volunteers demonstrate mitosis and meiosis to the rest of the group using hangtag chromosomes. Each person with a hangtag (see pics below) represent a chromosome and the entire room/class represents a cell.  The M = maternal, the P = paternal, and the color cloth (in this case, black) represents the the trait on a gene for that particular chromosome. Students are then lead through mitosis and/or meiosis as facilitated by the teacher. I need to ask if it would be possible to share the here and/or provide a link to the materials.


While this does not show the actual dance, I found it on YouTube and thought it was interesting...



And that's all I have for now and this session. Stay tuned for more...



Saturday, March 29, 2014

The Post-Antibiotic Era?


reblogged from jtotheizzoe:

The CDC has released a first-of-its-kind report detailing the threat of antibiotic-resistant bacteria to our health and food supply. It is not pretty.
Within the report (you can read it here, it’s very layman-accessible) lies threat assessments for a whole range of disease-causing microbes, from famous foes like methicillin-resistant Staphylococcus aureus (MRSA) to lesser-known dangers like Clostridium dificile and drug-resistant Neisseria gonorrhoeae(yes, that last one does exactly what you think it does).
Thousands of people are killed by such infections every year. They inflict billions of dollars of medical costs and lost wages. The drug-development pipeline for new antibiotics is almost empty. New tools like fecal transplantsand phage therapy are hopeful but still experimental, and at least a decade away. So what do we do?
The CDC calls for safer use of antibiotics, both in hospitals and on farms, and increased screening and vaccination efforts. But CDC director Tom Frieden put it plainly:
"If we are not careful, we will soon be in a post-antibiotic era."
Unless we do something to reverse this trend, and fast, it’s high time to tuck your head between your knees. We’re either on a plane that’s going down, or we’re about to get paddled. The choice of metaphors is yours.
For now, educate yourself, make sure your doctors are educated, call for action if you can vote … and if there’s any budding biologists out there, we’ve got plenty of new problems for you to solve. We’re gonna need your help.