Mineral or Non-Mineral?

Posted on February 28, 2010 by mysciencelessons

After chemistry, we head into our minerals and mining unit. First we have to figure out what minerals are. I ask them the question, “Can you SNIFC it? (c= ”k” sound) Of course, the kids have no idea what SNIFC means, so we go over what each letter stands for. I tell them that an object has to meet all 5 criteria, otherwise it is not a mineral.

S= Solids
N = naturally occurring
I = inorganic
F= formula, or fixed composition
C = crystal

Using a power point that I made up, in their small groups they decide if the item pictured on each slide is a mineral or not. I can’t answer any questions, I just say, “Can you SNIFC it?” Once each group decides, they write it down in their notes and I show the next slide. Once every group has decided, we go over the answers and I take surveys of how many they got right, which ones were hard for them to agree on, etc.

This whole activity took 25-30 minutes. Thanks to Marcia for the SNIFC idea!

Notebook:

pg. 124 – What is a mineral? Notes & PPT

Mystery Powder Lab

Posted on February 25, 2010 by mysciencelessons

One of our big labs of the year is the Mystery Powder Lab. I have 6 unknown white powders that the students have to identify by performing a series of chemical tests and observing physical properties. Once they have all their data collected, they use a flow chart to figure out the identity of each powder.

On a plastic tray, I set up the following equipment: one flask of vinegar, one flask of iodine, one flask of cabbage juice, 3 pipettes, cup of clean toothpicks, cup for used toothpicks, microwell plates, 6 numbered plastic knives, and a test tube clamp. I stress the importance of avoiding contamination and proper lab procedures. When the bags are not in use, they should be closed and put back, never put anything back into the bags once its been used or touched any surfaces (besides the knives), to only use knife # 5 for powder #5, not to let the pipettes touch the powders they are testing, if anything spills or breaks to let me know, etc. The plastic trays help keep everything contained, the powders do get messy and some stuff will spill or overflow. Very easy to clean up between classes when it’s all on the trays.

On the side of the classroom, I have the 6 mystery powders in small zip-top bags, 4 of each one. The powders are: baking soda, baking powder, flour, corn starch, sugar, and baby powder (no cornstarch kind). I have pre-cut aluminum foil squares for the heat test next to the bags, the students take one when they are ready to use it. Under the hood, I have candles set up for the heat test.

Students can test the powders in any order, as long as their data is written next to the corresponding number on their data chart. The tests that they perform are: Cabbage Juice to practice pH, vinegar to test for fizzing, and iodine to test for the presence of starch, and the heat test to test for sugar. For the heat test, you want a caramel color and bubbling for a positive test, all the other powders either scorch or don’t do much.

The students perform this lab in groups of 3-4 and it takes about 1 1/2 class periods to complete. Once they have collected all their data and made their observations, I give them the flowchart to identify the powders. As a group they evaluate their data and write down what they think each bag contains. We go over the answers the next class period, or if everyone is done before the end of class, we go over the answers then. Kids really enjoy this lab and work well as a group. They take turns doing the different tests and discuss what is happening during the lab.

Notebook:

pg. 118 – Mystery Powder Lab

pg. 119 – Flow Chart & Answers

Cabbage Juice Lab

Posted on February 16, 2010 by mysciencelessons

Today my 5th graders learned how to use red and blue litmus paper, as well as use cabbage juice as an indicator. In the classroom, I had 6 solutions for them to test. They could test the solutions in any order they wanted. The solutions were: tap water, salt water, baking soda, Comet cleanser, vinegar, and a freshly squeezed lime. The only solution they had to be careful with was the Comet cleanser, everything else was harmless.

Each lab tray had the following set up (1 tray had supplies for 4 people to share, but they worked in pairs):

One 125 mL flask of cabbage juice with a pipette
red litmus paper vial
blue litmus paper vial
12 clear plastic cups
1 large paper/coffee cup for used pH paper

On the side of the classroom, I had the 6 containers of solutions with a pipette in each solution. I used small take out containers I had at home. I have a habit of saving all types of plastic containers instead of throwing them out. As a teacher, they come in handy! I was able to set some stuff up at home and just add water to make the solutions when I got to school. The tops were pretty secure so it was easy to transport.

To test the solutions, they only needed 3-4 pipettes full of each item placed into their cups. Back at their table, they tested using pH paper first, then added the cabbage juice. When using the cabbage juice, 3-4 pipettes full was plenty to observe the color change.

They were able to complete this activity within one class period. The red cabbage juice has a strong smell, which they were all to happy to comment about it! =) I made the cabbage juice at home using half a head of red cabbage and boiling it for about 45 minutes to get a dark purple color. Once it cooled, I placed it into an empty soda bottle and filled it up about 95%. I added a small amount of rubbing alcohol to the bottle. This helps to keep it fresher longer and stop it from getting rancid too quickly. The rubbing alcohol does not change the properties of the cabbage juice or affect the pH. You can refrigerate it if you want to keep it longer as well.

Notebook:

pg. 116 – Cabbage Juice Lab

pg. 117 – Cabbage Juice Analysis

Water – Polarity Demo

Posted on February 13, 2010 by mysciencelessons

One of my students recently sent this video clip to me. (Thanks James!) It demonstrates the polarity of water by doing a rather simple experiment, I had never seen this before and can now add this to my bag of tricks! My unofficial theme for this year has been water. Everything we have studied so far this year, relates to water in some way. I tease my students and say that if they don’t remember anything else from 5th grade, they will know the formula for water! =) Enjoy!

“Meet the Elements” by They Might Be Giants

Posted on February 10, 2010 by mysciencelessons

Thought this was really cool… Note the formula for chalk is CaCO3 not CaSO4.

pH Scale Activity Sort

Posted on February 10, 2010 by mysciencelessons

To introduce the pH scale, I created a partnered activity where students would place an example for each pH value according to 15 clues that were provided. Each student had a pH scale that I had printed on the color laser printer at school and had pre-cut for them. They glued it into their notebook, towards the edge of the page.

On card stock, I printed the same pH scale in color. I also printed out the 15 examples and cut them apart so that each one formed a rectangular tab. To keep things organized, I labeled the plastic bag with the group #, and wrote that same group # on the back of each tab so that if they fell out or got mixed up, I could place the sets back together again.

To start the activity, I handed each person the colored pH scale to glue into their notebook. When they were done, I had them close their notebooks and put them under the table so they had room to work. Then I handed out the cardstock version of the pH scale and one bag for each set of two students. They removed the tabs from the bag , spread them out, and counted to make sure they had 15. We reviewed where the acids were (pH less than 7) and where the bases were (pH greater than 7). I explained how I was going to read clues and they had to place the tabs into the correct spots on the pH scale and, at the end, we’ll see how many they got right. (It was like a game, not for a grade)

I read the clues and they worked with their partners to place the tabs where they thought they belonged. After the last clue, I gave them a minute to finish their pH scale and ask for repeated clues if they needed to. Once everyone was ready for the answers, I told them that if their tab was in the right spot, to leave it there, and if it was wrong, just slide it to the side. Do not make any changes. I revealed the tab that belonged to each pH value one at a time. At the end, we took a survey to see which partners had the most right. Some kids got 13/15, some had less than 10 correct.

We cleaned up and took out our notebooks. On the SmartBoard, I pulled up the answer key and we copied the answers next to each pH value. Once their notebooks were up to date, I played the BrainPOP movie about the pH scale. I then handed out the activity page and they glued it into their notebooks. With a few minutes left in class, they started their hw.

The kids listened carefully to the clues, they collaborated with their partners, they used information from the pH scale to place their answers, and they wanted to do well. It was funny, when they got an answer right, they whispered ”yes!” and anticipated the next answer to see how many they would get correct.

Notebook:

pg. 114 – pH Scale Activity Sort

pg. 115 – BrainPOP pH scale activity

BrainPOP Movie: pH Scale

Law of Conservation of Mass

Posted on February 10, 2010 by mysciencelessons

What I love about this lab:

brush up on TBB skills
following directions skills
making observations
observing a chemical reaction
formation of a gas
mass of a gas
an endothermic reaction, bottom of flask gets pretty cold!
reading a chemical equation – shows that same elements are present before and after the reaction, no new elements are introduced or formed.
formation of new molecules, the atoms are rearranged to form new substances that were not in the flask before.

The one thing that is not very clear to the kids is that the mass of the system before the reaction and after the reaction should be the same. Their results consistently show a loss of about 1 gram (on average) without releasing the gas from the balloon. When the gas was released, there was an additional loss of about 1 gram.

For this experiment, there are 2 factors that can make the final mass different. The first factor may be leakage: gas, liquid, or both escaped during the active part of the chemical reaction. The seal formed where the balloon meets the flask may not be 100% airtight, even with the kids holding it. But if leakage does not happen, the second factor is buoyancy. When the balloon fills up with CO2, the volume of the balloon increases, therefore displacing the air around it. NSTA published a study about this and had results to show that there was a relationship between the volume of the balloon and the decrease in mass for the closed system.

Here is an excerpt from the published article: “Because the apparent loss of mass is not due to leakage, this relationship clearly demonstrates a buoyant effect. Archimedes’ principle states that any object submersed in a fluid will displace a volume of fluid equal to the volume of the object and the mass of the object will be reduced or “buoyed up” by an amount equal to the mass of the fluid displaced. Hence, when measuring the mass of an object in air (a fluid) on a balance, the mass that is measured is the conventional or apparent mass of the object. The true mass of the object would be the mass that would result if the object were massed in a vacuum.” (Science Scope, 2008)

A better example to show conservation of mass may be to place an ice cube or two in a small plastic snack bag, and to take timed measurements as the ice cube melts. (In a humid classroom, condensation forming on the outside of the bag could alter results.) Also, if using baking soda and vinegar, using a soda bottle without the balloon and capping it would keep the volume the same.

Overall, the kids enjoyed this experiment and it covered a lot of concepts that we studied. If you have done either of these experiments, please share your results!

Notebook:

pg. 110 – Law of Conservation of Mass

pg. 111 – Conservation of Mass Analysis

Acids & Bases Venn Diagram, Notes

Posted on February 8, 2010 by mysciencelessons

Group SmartBoard Activity (25 minutes): For this activity, I broke it up into 5 parts.

Part 1: General Discussion about acids and bases, pH, and indicators. Most 5th graders didn’t really have a lot of prior knowledge on this topic.

Part 2: Explained how they were going to watch a BrainPOP movie on acids and bases, and to listen for facts presented in the movie. Using the list of facts on their handout, they were to write an “A” next to the facts that related to acids, and a “B” next to facts that related to Bases.

Part 3: Gave the students about 3-4 minutes to compare their fact lists with their lab partners. They may not have all the facts categorized, and that was ok.

Part 4: I explained how one person from each group was going to come up to the board and drag one fact into the Venn Diagram. If they were correct, everyone wrote that fact into the Venn diagram on their handout. Students had to choose who would go up for each turn, and what fact they would place. It was a good opportunity for collaboration and coming to a consensus. If the answer was incorrect, they had to drag the fact back to the bottom of the board.

Part 5: Go over all the answers, make sure that their notes reflected the notes that were on the board.

The activity worked really well, the students were on task and it was a nice way to introduce new information in an interactive way.

I uploaded the notebook file to SMART Exchange, not sure if its fully functioning yet, here is the link.

Notebook/Links:

BrainPOP Movie – Acids and Bases

pg. 112 – Acids/Bases Venn Diagram

pg. 113 – BrainPOP – FYI – Gastric Acid

Balancing Equations

Posted on February 8, 2010 by mysciencelessons

Last week I showed the kids how to balance chemical equations. We used a lesson that I started using about 13 years ago when I taught 6th grade. Last year I thought I’d have the 5th graders try it, and was really impressed with how quickly they got the hang of it. This years class was balancing equations like pros, too!

By this point in our lessons, the kids are very familiar with recognizing element symbols, counting atoms, and reading chemical formulas. I showed them how chemical equation have two sides: products and reactants. I also introduced the “yields” symbol and how to read an equation. Having the laminated cards, as well as the color coding, allowed the students to process the information visually, tactilely , mathematically, and verbally.

They worked in pairs to set up and solve the equations. I introduced the first equation to the class and how to count the atoms on either side of the yield sign. Then I explained that it was like solving a puzzle, or balancing a see-saw. You want the same amount of “stuff” on either side. And the only way to solve it, was pretty much by trial and error and don’t be afraid to make a mistake. I also explained that only the coefficients could be added to the front of a molecule, and they couldn’t change the subscripts.

At first, they were a little intimidated and looked at me like “OMG, this is impossible!” I told them they could do it, just relax, try it, and then ask me for help if you get stuck. With a little encouragement, they got started and once they solved the first one on their own, they were on a roll! They worked at their own pace and solved the equations in any order they wanted. I didn’t expect them to finish all the problems, but most kids solved 70% of the problems, those that worked faster did more, and those that needed more time, did less. I floated around the room and monitored, checked work, and helped as needed.

The students called me over when they had a balanced equation so I could check their work before they moved on to the next problem. The kids were on task, talking about the equations, setting up equations, placing the coefficients into the equations and quickly swapping them out as needed, and they were excited. It was almost like a game for them. For some of the kids, they could just look at the equation and figure it out in seconds!

Notebook/Links: