Separating Mixtures

In follow up to our lessons on elements, compounds, and mixtures, we talk about how we can separate mixtures.  Our curriculum requires us to teach 4 different separation techniques: filtration, evaporation, magnetism, and screening.

The first day I introduce this, I give small demonstrations of each one. 

• I make a mixture of salt water and have that boiling throughout the lesson until it's all gone and only the salt is left.  
• I have a screen and put a mixture of rocks and dirt through it.  
• I have a filter and put some stuff through it. 
• And then this year another teacher let me borrow her mixture of iron filings and sand with her magnet, so we got to show the kids that one as well.  (I also took the kids outside and showed them that the magnet will pick up the iron in the dirt.  One kid came back the next day and said he tried that in his backyard and it worked. Happiness.)

We don't spend much time on this, so there's just a few activities plus a couple of worksheets.  Here's the worksheet I created for this:

Click below for worksheet

Photosynthesis and Respiration

This is a great unit with my seventh graders.  It's easy to start because the kids usually remember something about photosynthesis from elementary school.  If not, they already know that plants need sunlight and water.  This is not a very long unit.  Maybe 2-3 weeks.

The goals for this unit are:

• The students will be able to write the word equations for photosynthesis and respiration
• Photosynthesis is
  "sunlight + water + carbon dioxide --> glucose + oxygen."  
• Respiration is
  "glucose + oxygen --> ATP energy + water + carbon dioxide."
• The students will identify that photosynthesis occurs in the chloroplast and respiration occurs in the mitochondria. 
• The students will identify that they are reverse/opposite reactions.
• The students will understand the words "reactant" and "product."
• The students will use their knowledge of the reactions to answer various questions.

Some (not all) of the activities we do for this unit:

1. Acting it out!

I have little cut outs from card stock paper (nothing fancy!) and one kid is assigned a role (either a reactant or a product, or the plant).  I make up a little narrative and the kids have to listen for their part and come in and "act" it out appropriately.  It's just a fun little activity, but it gets the kids up and moving and helps them visualize what's going on.

This class actually happened on Halloween this year, which was perfect.  None of my kids dressed up for school (sad!) so I told them I had brought their costumes: sunlight, water, carbon dioxide, glucose, oxygen, and a plant. haha.

2. Worksheet practice:

Worksheet practice throughout the unit, used in whatever order makes sense for that year and how that group of students is progressing.   This is only two of my worksheets.  The others ended up as a mix of things from other sources that are not directly mine, so I'm not putting them on here.  I know I've got others, but they're probably on my work computer (I'm on my home computer right now).  If I find them I'll put them on here, too. 

(Get the worksheet at the bottom of this page)

Worksheet A: Identification

 

WORKSHEET B: Chemical Formulas

I use this more for my 8th graders who are working on the periodic table and interpreting chemical formulas.  It reinforces what they learned last year and applies their new knowledge to familiar situations. Link for worksheet at the bottom of this page.

3.  WALL-E Day!

from google image search

No, we don't watch the whole movie, although that would be awesome and less planning for me!  But there's no time to do that and it would be a waste when a few clips can aid your discussion quite nicely.  The kids love this class because we get to watch some of WALL-E and understand that it actually has real science in it!

The clips I show (I may or may not show all of them)
       1. Opening Scene
       2. WALL-E's day at work
       3. WALL-E finds a plant
       4. WALL-E first date scene (EVE takes the plant)
       5. WALL-E in space
       6. Human dystopia
       7. Directive A113
       8. End Credits (I show this so we can talk about what the people are doing and how the earth changes)

WORKSHEET FOR WALL-E (link at bottom of page)

4. Yeast Lab:

It's hard to tell, but the red balloon is a little bigger.

It would be fun to also do a plant lab, but I haven't figured out how to do one of those in our small little country school with limited resources.  So yeast lab is how we'll have to do it! The kids love watching the balloons fill up. I use this towards the end of the unit to really push their thinking and application of what they have learned.  Deeper level questions like "How can you prove the yeast are doing respiration and not photosynthesis?" (possible answers: we added sugar as a reactant; they're not green, so they don't have chloroplast; etc.) "What is filling up the balloon and how do you know?" (CO2, because it's undergoing respiration).  My kids have a harder time with these questions that make them think.  It takes more prodding as a teacher to get these SPED kids to that level.  We can get there, it just takes longer.

LAB WORKSHEET (link at bottom of page)

 

And that's photosynthesis and respiration.  We do a lot of group lecture, discussion, and practice.  I draw a lot on the board and I have them practice the equations every day.  Today was our last day on the unit, but we have two days of review before our cell test (the overall unit), so we'll have some talk on it before the test next week.

Frog Dissection

Ah, yes.  That wonderful day in middle school science that everyone remembers.  A right of passage, almost.

The frog dissection.

The last unit in our syllabus was supposed to go over some parts of physiology.  I ran out of time (though some of the points I was able to cover in other units), so I tried to make up for it by explaining what they were looking at during the dissection.  Lame?  Maybe.

I was late to class today.  We had a meeting with the principal that went over time into the next period.  After it ended I had to race to get the trays for the frog dissection, then race to my classroom.  I found the security guard letting them in.  "Oh, please, no.  I have frogs in my classroom and I don't want students in there unaccompanied."  I don't know why you would let students into a classroom without the teacher in there anyway, but I'm glad I got there right as they were entering.  Can you imagine the disaster???

Hypothetical Situation
Student 1:  look!  A bag full of frogs!
Student 2:  Cool!  Let's poke it!
Student 1: Okay!
 . . . poking ensues until the bag is in shambles, liquid spilled on the floor, and frogs are being thrown across the room  . . . 

Yeah. . . I don't want that to happen!!

The students came in and sat down.  I gave a very quick and stern introduction.  There is no horseplay when we have the frog on our tables.  There is no walking around.  There is no waving of the tools.  There is no playing with your frog.  This is your last warning and if I see any of these behaviors you will be sent immediately to the office to spend the remainder of the period.

The kids were pretty good with understanding that they had to be on their best behavior today.  They figured out that I wasn't mad, but good behavior was important today.

It was fun.   Lots of exclamations throughout the period.  I put the lab instructions on the projector for them all to see and we went through the instructions together.  That made it easier for us all to be on the same page rather than having them follow the instructions at their own pace.

Everyone was on good behavior and the dissection went smoothly.

I had two class periods in a row that did this dissection.  By the end of the second the smell was getting to me!!  I had both classroom doors open with the air vents on their highest setting, just to try and get the air circulated well enough.  However, it wasn't until the end when we had cleaned everything up and clorox wiped the tables down that it started to smell better.

Yay for adventures and clean classrooms.

Skeleton Reconstruction Results

My kids did a great job!  They loved this.  This was a really good learning opportunity.  My favorite part was showing them the pelvic bone and the femur and demonstrating how they fit together as a ball-and-socket joint.  That one was a favorite.  What other opportunity do kids get to manipulate real bones?

Just finished.  You can still see the glue still wet on some of them. 

Owl Pellet Skeleton Reconstruction

The last step of our owl pellet lab is here!  (See part 1 and part 2.)

The kids are taking their washed bones and gluing them into a complete skeleton.  For their reference, I'll have the following image on the smart-board for them all to reference throughout the lesson.

Click here for image.

The rubric requires the following things: bones placed correctly, missing bones drawn in, bones labeled correctly, neatly done.  The kids and I will work together beforehand to determine what exceeds expectation, meets expectation, and doesn't meet expectation for each criteria.  

In the end, it will look something like this.  This is my example I did for the kids to look at.  

You can already see there are a few scientific terms I'm not worrying about for my sped kids: mandible (jaw), metacarpals (fingers), metatarsals (toes), innominate (I'm using pelvis instead), and I'm not doing sacrum at all.

This should be lots of fun tomorrow. I'm excited about it. :D

Owl Pellet Dissection

This was an awesome class.

Have you ever dissected an owl pellet before??

Do you even know what an owl pellet is?  Well, let me inform you.  An owl will swallow it's meal whole, usually.  However, it does not digest everything it eats and the only way for it to get out safely is for the owl to regurgitate it.  Thus, a ball of hair, bones, and saliva are excreted from the owl's mouth.  The pellet.

Owl Pellets for use.  They seem small, but you'd be surprised how many bones you find inside one pellet.

Sounds disgusting, right? Yeah, well, it is if you think to much about it.  I had one of my students put on a permanently disgusted face the whole time I was explaining our task for the day.  But once you get into it you kind of forget what you're working with and just focus on discovering all of the bones in your pellet.

Can I just say that I have never had an entire group of middle schoolers so quiet and captivated for an entire 40-minute period?  They loved it.

Our beginning Bell Ringer.  The writing on the poster was small, so I allowed the kids to come up to the board to get their answers.  The red answers are what they told me after everyone was done.  

One of the posters in our board.  This was a great visual to use.

This dissection was optimally placed in our curriculum.  The kids had just taken a 3-day test and were exhausted.  No one wanted to do any work (teachers included).  So I scheduled our dissection for Thursday––after the test and right before spring break (another reason no one wanted to do any work). In and of itself it is engaging, and there is so much you can learn in a single session.  Plus, the kids are basically discovering and teaching themselves, so all the teacher has to do is facilitate that flow of knowledge.

This was the poster-sized bone chart.  Each partnership also had their own bone chart to use.

All of the posters in the class that day.  Available for students to use and compare their own bones to.  

What you learn in an owl pellet dissection:

• Lab safety
• Food Webs––what is the owl eating?
• Physiology––digestion of owls and bone structure of small rodents.  Also, how many animals can an owl eat at one time?
• Scientific Inquiry––what animal does this skull belong to and why do I think that?
• Environmental Factors
• Ecosystems
• Evolution –– common descent with bone structures
• Anything you want 

This can be done in one class period, or you can extend it into an entire interactive project.  I'm going to try and extend this project out. Not only are we done with testing (thus, relaxing the schedule a bit), but this is an engaging project and many students have already asked the next steps, i.e. what are we doing with the bones we've found?

So I'm excited.  The kids are excited.  This is an excellent project for any age.  The pellets are a bit expensive, but believe me when I say they are totally worth it.  TOTALLY.  So worth it that every year our principal buys enough for the entire 7th-grade to do this dissection. 

This video came with the materials, I think.
It was a great 15-minute introduction to Barn Owl life and the Owl Pellet Lab.

Starting the dissection

They split their pellet in two so they could each work on a section.

Very cool discovery––a skull!  A hairy skull, but a skull nonetheless.

One group's pile of bones. 

The Scientific Method & Bias

The last day of Review week I decided to take all class reviewing the scientific method.  We had just finished our ecology unit, so I didn't want to take time reviewing that again.  There are probably going to be questions on the test dealing with making a hypothesis or conclusion, or evaluating bias, so we needed to spend time on that.

Because the term bias was newer to kids, this was a little slower than the last two days of review.  Basically, this day wasn't review at all, but just test-prep.

Also, notice that each day there is an additional Brain on our worksheet.  Our brains are getting stronger.  Isn't that cute????? :)

Orienteering

New Mexico Grade 8 Science Standard I (Physical Science):  5-8 Benchmark III.
 #6:  Know that the Earth has a magnetic field.

This could be a 2-minute lecture on the earth having a magnetic field.  But when it's the last day before spring break, why not make it an entire 90-minute class period?

Welcome to Orienteering 101!

I handed out the little compasses to each student and we practiced learning how to use them.  Always remember that North is with North.  Then find your direction.  

I then took the class outside to the baseball field. I had closed it off to everyone else with big signs, and during my prep period (there have been many times I’m grateful that prep is first for me) I set up the orienteering course.  It took me about an hour to get everything set right, and then the rest of the period to perfect it and get everything ready

 

My first class did awesome.  They were in groups of two and each had a different course to take.  There were 8 markers around the field.  They got their first clue from me in the center, and then went off in the direction of their clue.  There they would find a new clue for their group that would send them in a different direction to another marker.  The first group back to me with all of their markers in the correct order won and got a prize.  It was fun, because the first group back actually didn’t have their markers in the correct order, so I sent them back at their second marker where they had first messed up.  They ran back.  I had a couple other groups come back with answers really close, but had 1 or 2 wrong.  In the end, we had a winner.  There were only 15 minutes of class left when everyone had finished (of a 90 minute class), and it being the last day of the week I told them they could do whatever.  Some joined the PE class on the next field in playing soccer.  Other sat in the shade of the dug-out.  I went around and made sure all of my clues were at the right markers and then sat in the dug-out with my class.  

My second class came in and didn’t do as well.  They could not figure out that North had to go with North.  They were trying to get the needle in the compass to move instead of physically changing the direction of the compass to match the needle.  I still had a winning group, but it was harder with this group.  I think it’s a combination that I missed a step in my introduction and that this groups had a higher percentage of lower abilities than my last class.  Also, it was much hotter this time.  But we only had to do this for half the class because this class had finally earned their class party.  After the winner came in, I gathered them all up and we went back inside.  They were good enough to help me pick up the markers and take down the signs before we left, though.  Then they sat in my classroom for the party where they ate chips that they brought and listened to music.  It was pretty chill.  But it worked.  :)

An example marker.  The Marker paper should be under the rock.  This is what happens after kids have been by. 

Magnetism

This will be a worthwhile post.   I'll not only tell you how to do cool experiments with your kiddos, but how to get your very own iron filings for free.

Hear that?  FREE Iron Filings!

When you have iron filings you can do cool experiments like this with the kiddos:

Pretty Magnetic Field Lines

I cut the corners of a piece of paper and folded them up to make a tray.  That way the iron filings wouldn't go everywhere.

I wish I could have let the kids try this on their own, but I don't trust them enough––I can see iron filings going everywhere and kids accidentally breathing in too much iron and then dying.  Not the best situation you want to be in as a teacher.

So instead we did a demonstration where they all stood around one table and watched.  It was cool and I the kids really liked it.  They also all asked me if they could do it themselves.  Since I don't want anyone dying, I said no.

Now for the part you've all been waiting for: How to get your very own iron-filings for free.


Method #1: 
Grab an old iron or steel nail and file it down with a heavy-duty file (not the wimpy kind you file your nails with, but a "manly file," as my husband called it.)  File down the nail.

I actually did this method for an hour during my Saturday afternoon.  I didn't get very much iron.  There was a small lump, and I could do some things with it, but you really don't get very much.



Method #2:
Place a magnet in a plastic bag.  Go outside. Rub the plastic bag in the dirt.  Lift and shake. There should be iron on the outside of the bag, attracted to the magnet.  Put this in a cup and take the magnet out of the bag to release the iron into the cup.  Tadaa!!  Repeat, repeat, repeat, repeat.

Depending on how much you want, this can also take a while.  The ASL interpreter in my first class told me about this, so during lunch I went out for ~5 minutes and just played in the dirt collecting iron.  It was awesome.  I got enough for our little demonstration above for my next class.

My little collection of iron filings from 5 minutes of Method #2.

I did also collect some dirt with this method.  So I took my dirty iron mixture and purified it even more by moving it from the cup to the final container using the same magnet-in-a-bag technique.  That lessened the amount of dirt quite a bit.  I used this second separation in my demonstration.

Method 2 would be a fun activity to do with your kids, too.  Make them go out and collect

real, natural iron from the EARTH!!!

and then use it to learn more about magnets.  (This could also go with any mixture separation lesson plans you may be doing.)

Yay for magnets.

Electric Circuits

On of the great memories I have from middle school science is learning about electric circuits. We would go to the lab room and get to fiddle around with all of the wires, batteries, light-bulbs, and whatever else there was at our disposal.  I knew when I got to this unit, that I would have to let my kids enjoy the same experimental freedom.  There is more power in doing the science than in reading about it.

For this unit, I always have a little lesson at the beginning, then sometimes a little worksheet to make sure they are understanding.  Afterwards, they have their little experiment they have to do.  If they are done, I let them play around with the materials before the end of class.

Oooh . . Science!
Apologies for my lame phone picture quality

We have done the following experiments:

1. Conductors and Insulators –DAY 1
2. Build a simple circuit –DAY 2

• Materials:
• A battery (no battery holders), 
• A free light bulb, 
• simple wires (no alligator clips) 
• Make the light bulb turn on, then draw your circuit and label the following:
• Conductor
• Insulator
• Power Source
• Light Bulb 
• (the gen-ed classes labeled this as "resistor."  I did not worry about that term with my kids. I wanted them to focus on "conductor" and "insulator" and understanding how a circuit works.)

3. Build a working series circuit –DAY 3

    Build a working parallel circuit –DAY 3

• Materials:
• 2 batteries (with battery holders)
• 2 light bulbs
• wires (with alligator clips)
• 1 switch
• Make the light bulbs turn on, then draw your circuits and label the following in each circuit
• Conductor
• Insulator
• Power Source
• Light Bulb **see note above
• Switch

5. Exploration with series and parallel circuits –DAY 4

• The lesson I had at the beginning of this class was two fold: review series and parallel circuits and practice drawing circuits correctly using symbols.  We used the mini white boards for this lesson so each kid could practice drawing the circuit instead of just watching me draw it. 

• For this experiment I wanted them to continue solidifying series and parallel circuits and to play around with the variables in a circuit.  How do you get a light bulb brighter? What happens when you have a lot of wires?  I had them follow this worksheet to get going.  The kids could go at their own pace on this one, which is what I loved about it.  For those who finished fast, I had a challenge circuit for them to build for extra credit.  

Natural Selection Project

We don't have very much time for our evolution unit.  In fact, I'm only budgeting two classes for this (which stinks--one of my classes didn't even get to me today. The testing schedule was so crazy that our last class never happened and our third block just lasted twice the time.).  We have this week for evolution, then next week is REVIEW THE ENTIRE YEAR, and then the week after that is the big science tests.

Yay. Right?  Yay???

Anyway.  Because I didn't have much time, I had to make these two days good and worth it.  Today the lesson was focused on Natural Selection.  Thursday's lesson will be on classification, with a focus on reading and making dichotomous keys. 

I was SO excited about this lesson.  There were a lot of good interactive parts.

We started out with this Power Point activity:

Then we went to this website to play the actual game.  The online game allows you to make mutations to see if that can prolong your time on earth.  The kids loved it.  It's a fast game, so I had 3-4 students come up and try their hand at it.  Click here to go to the game.

Afterwards, we learned about Charles Darwin in this Power Point.  Who he was, what he did.  We talked about what evolution is and what natural selection is.

Then the kids had to create a project, which was indicated on the last slide of the second Power Point.  My example is below.  This is what I drew at home the night before.  In class I colored it up a bit to make it nicer. 

Example Student's project (kind of hard to see--the only camera I had available was my computer camera, and it's not very good. Apologies!)

The kids did really well with this assignment. I was pleased with the outcome. There was one last step, and that was to take their data from the chart at the beginning and make a graph from that.  This graph was attached to their project to show whether or not their species actually survived.  The graphing was hard for my kids.  We all figured it out eventually.