The law of conservation of mass states that mass in a closed system will not change before and after a chemical reaction. Mass isn't created or destroyed, it just moves places. Seems simple enough, but this law can be difficult to demonstrate. It seems nearly impossible to get PERFECT data every time. And when the measurements are off by two hundredths of a gram, students are often yelling "Ah-Ha! Lavoisier was wrong!" (Sigh.....) BUT, it can lead to good discussions on where any change in mass could have come from.

Here are some labs you can use for different grade levels to teach the law of conservation of mass.

Grades 5-6:  GLOW STICKS
In this experiment students compare the mass of a glow stick before and after it has been cracked and activated. You should get relatively good data for this lab, but as you can see in the picture the mass decreased by a hundredth of a gram. Glow sticks can be found at the dollar store, or stock up on them after Halloween when they go on clearance.

Grades 7-8: ALKA SELTZER BAG
In this experiment, students compare the mass of water and alka seltzer in a Ziploc bag before and after it reacts. I'll admit this is a tough one to get great data because the bag is porous and some gas will escape during the reaction. However, it's best to use a bag instead of a sealed container because with a sealed container the lid can pop off from the pressure. I've found thicker name brand bags work better than store brand, so don't skimp to save a few bucks.
One thing you can do after the alka seltzer and water reacts is to let students open the bag, release the gas, and re-weigh (see the last picture on the right). They will see a decrease in mass and learn that gases (in this case, carbon dioxide) have mass. If you'd like to check out the lab worksheet, click here.

Grades 9+: STEEL WOOL
In part 1 of this experiment, students compare the mass of steel wool before and after pulling it apart. Since it is only a shape change and not a chemical change, it's relatively easy to get perfect data as long as they pull it apart over the scale (small fragments will fall off).
In part 2, students burn steel wool and compare the burned mass to the initial mass. (Bunsen burners will give you better data than using matches or candles). What is interesting about this experiment is that the steel wool actually GAINS mass after burning. This is because as it burns it combines with oxygen in the air to form iron oxide. The addition of the oxygen atoms causes an increase in mass. It's a great experiment to get students thinking about chemical reactions and where this additional mass could have come from. If you'd like to check out the lab worksheet, click here.

Do you have any other ways you demonstrate the law of conservation of mass with students? Leave me a comment!

Normally volcanoes form at plate boundaries, but hot spots are an exception. Hot spots are areas in the mantle that are exceptionally hot, and form plumes that break through the crust. They are great evidence of plate tectonic movement because they form island chains. Take Hawaii for example- the big island of Hawaii is directly above a hot spot and is still actively growing. The further you get away from the hot spot, the older the islands are. That means Kauai is the oldest of the chain.

For a long time I was looking for a way to demonstrate to students how hot spots work. Here is a great demo you can use that only requires a few materials: an aluminum pie pan, cornstarch, water, and a candle. Check out the video to see it in action:

If you'd like a lab write-up for students, you can find it here.
Have fun!

Bored of teaching the carbon, nitrogen, water, or rock cycles? Spice things up by having students take a ride through each of the cycles with these interactive games!

In these games, students will roll a die at stations throughout the cycles and pick up paper tokens along the way. For example- in the rock cycle game, the stations include: igneous, sedimentary, and metamorphic. In the water cycle game, stations include: clouds, plants, oceans, animals, groundwater, soil, lakes, rivers, and glaciers.

To set up the game you will need to print out station cubes and fold them (cardstock works best and will extend the life of your cubes). You will also need to print and cut station tokens and place them in cups around the room.

Assign students a random station to begin at. They will start each round by picking up a paper token and placing it in their cup. Then they will roll the die and see where it tells them to go next. I let my students go at their own pace and tell them once they have 15 tokens in their cup to head back to their seats. Then they tally up where they have been and start answering the questions on their lab paper.

Students really love these games and often ask to play again the next day. I also love that it solidifies how things move through the cycles and you can even discuss where things are stored throughout the cycle. For example- in the water cycle, water molecules can be frozen in glaciers for hundreds of thousands of years. Or in the carbon cycle, carbon can be stored in fossil fuels for millions of years. If students get stuck at a station over and over it's good to discuss why.

Want to check them out for yourself? Click on the images below!

When I moved to my current school the department chair made it clear that we should "teach bell to bell." I understand the logic in this, and sometimes class does last exactly 50 minutes. But if EVERY teacher taught bell to bell EVERY period, students would never have time to give their brain a break. I think it's okay to give students a few minutes break here and there. I'm not suggesting let them sit on their cell phones, there are some other options! Below is a list of brain breaks you can try with high school students.

WAYS TO GIVE SOME STUDENTS SOME DOWN TIME:

• BRAIN TEASERS- Here are a few from scholastic or you can check out a book from your school library.
• LOGIC MAZES- I put these up on the board and have students try and work through them.
• HEAD DOWN AND BREATHE- Have your students do nothing for 2 minutes. It's relaxing!
• PLAY A SONG- Make sure to type in "clean playlist" on YouTube so you can avoid songs with bad language.
• COME UP WITH A HANDSHAKE- with your shoulder buddy
• ROCK PAPER SCISSORS
• THUMB WRESTLE
• YOUTUBE CLIP- Here are some great science options!
• PRESSURE POINT MASSAGE- Here are a few options on your hands.
• WOULD YOU RATHER- Here are some sample questions (scroll down to high school)
• METAL PUZZLES- I find the small metal puzzles at the dollar store. They come with 2 pieces that students have to twist and turn to figure out how to separate.
• TIC TAC TOE- do on the back of your notes page
• WALL SQUATS
• WALL COLORING- Hang some coloring pages on the walls and allow students to color for a few minutes during down time.
• GRAFFITI WALL- If you aren't familiar with graffiti walls, check out this blog post from We Are Teachers.

WAYS TO KEEP STUDENTS WORKING WITH A PICK-ME-UP:

• QR CODES- Use a QR code generator to add QR codes to your activities. You can link to youtube clips, virtual labs, or interactive games.
• SCAVENGER HUNT ACTIVITIES- You can have students complete an ecology scavenger hunt outside or a lab safety classroom scavenger hunt at the beginning of the school year.
• CARD SORTS- I have students work on these with their shoulder buddy to review new concepts.
• CLOCK PARTNER DISCUSSIONS- When you allow students to pick a partner to work with, they tend to pick the same person every time. Have them set up clock partner so you can change up who they work with. (If you Google "clock partner worksheet" you can find a ton of free examples). Then you just tell students "go work with your 9:00 partner."
• QUIZLET LIVE OR KAHOOT- If you have computers or cell phones available, these two review games are always really fun.
• WALKING WORKSHEET- Post worksheet questions on the walls around the room and have students walk around the room while they complete the questions.
• ANIMAL LIVESTREAMS- Have students take a short break between working and have them watch an animal livestream on the board. Here is a list of options.
  

Remember, it's OKAY to give your students a quick breather! Have any other activities to suggest? I'd love to hear them in the comments!

Teaching English Language Learners (ELLs) can be so fun and rewarding. They are some of my favorite students to work with. They tend to be hard working and driven. (You may want to check out my blog post with 10 tips for teaching ELLs in the science classroom).

The main categories ELLs are tested on in order to become "proficient" English speakers are reading, writing, listening, and speaking. As science teachers we can support the ELL teachers by weaving these into our daily curriculum. I have some tech tools to share with you that will make these easier!

READING
Students need to practice reading in all their classes, not just English. I try and find fun and engaging articles for students to read, not excerpts from the textbook. (Not sure where to find free articles? Check this blog post). Now, you can't hand out an article to your general ed. students and expect your ELL students to be able to read it. But the good news is there are ways to change the lexile! If you find articles on Newsela they have different lexiles built in. If you find an article elsewhere, all you have to do is copy and paste the text into a free site called Rewordify. It will make the text simpler and easier for your ELL kids to digest. Check it out!

WRITING
I don't assign a ton of writing assignments in my class, mostly because grading it is way too time consuming. And honestly as a science teacher I'm not trained on how to teach writing. BUT, we aren't completely off the hook. We can still at least give students writing opportunities because the more they practice the better they will get.
One easy way to add some low-stress writing to your curriculum is by assigning writing prompts. I would provide writing prompts to the students before we learned a new concept. Assigning it before the lesson is taught has a few purposes aside from writing practice: it gets them thinking about the concept and shows me any misconceptions they have going in. That way I can address them as we go. Looking for science writing prompts? Check out this blog post.

LISTENING
When you are addressing the class as a whole, often times you are talking way too fast. ELL students benefit from you talking slower so they can listen better and digest. If you are giving lab directions or even a lecture, you can always record yourself (with Vocaroo or Screencastify) and post it on your class website for them to refer back to.
Another cool tech tip is that students can have website content read aloud to them. Here are directions on how to use the Google Read Aloud extension.

SPEAKING
ELL students need plenty of opportunities to practice speaking English. It is okay to have a loud classroom, as long as students are on task! However, one thing I've found is that ELL students often get nervous or shy speaking in front of their English speaking peers. One low-stress way you can have students  practice their speech is by having them submit their work through an audio recorder like Vocaroo. I love Vocaroo because 1) it's free! 2) there is no login required, and 3) it's fool proof. There is one button to push- the record button. No learning curve.
For example, if you have your class participating in a Socratic seminar or doing a whiteboard CER session, you can have your ELL students record their part on Vocaroo. They can submit the audio via email and you can grade with a click of a button. Super easy for you and very low stress for them.

Any other cool tech tools you know of to support reading, writing, listening, or speaking skills? Drop them in the comments!

Fall is by far my FAVORITE time of year. Seeing the leaves change color is truly the highlight of my year. Are you looking to bring some fall or thanksgiving themed activities into your classroom? Here are some ideas:

The best part of thanksgiving is the meal, but do students think twice about how far that meal traveled from farm to plate? In this lesson students learn about "food miles" and calculate how far an average meal traveled before it hits your stomach.

Save some of your food scraps from your thanksgiving meal prep and have students re-grow vegetables. It works great with lettuce, celery, onions, and carrots.

One thing you often see outside or in your fall centerpiece are acorns and pinecones. But have students thought twice about why those seeds have adapted to be so hard or spiky? How does it benefit them? Students can explore seed adaptations and dispersal mechanisms.

Does eating turkey really make you tired? In this free lesson from Biology Roots, students will learn about tryptophan and see if it really causes thanksgiving zzzzz's.

Why do leaves change color in the fall? In this experiment, have students try out leaf chromatography.

Speaking of leaves... grab some fall leaves from the ground outside and have your students make preserved leaf skeletons! They can learn about leaf anatomy and what travels through those veins. You could also discuss how decomposed leaves return nutrients to the soil.

Have a leftover pumpkin from Halloween sitting on your porch? Bring it in and have students learn about the process of decomposition. Or, cut off the top (with seeds left inside), throw in some soil, and watch em germinate!

Want to throw in some graphing practice? In this free lesson from Science with Mrs. Lau, students graph turkey gobbles. Graphing practice is always a good use of time!

Around autumn you can always find variegated corn in grocery and craft stores. They are a great way to introduce genetics, dihybrid crosses, and chi-squared analysis.

I hope you have a great time trying out some of these activities with your students! And I hope you have a great thanksgiving holiday with your loved ones. Remember, your students are very thankful to have you in their lives even if they don't often say it.

Have you ever tried out choice boards with your students? I love them because they give students some voice and choice in their learning. Choice boards provide a variety of ways for students to demonstrate they have mastered a concept. Your students that love to write can choose to answer writing prompts, your students that are artistic may choose to create an animated cartoon, and your talkative students may choose to use an online voice recorder to explain what they learned. The possibilities are endless.

If you make your own, here are some options you could include:

• Virtual labs
• Website review games
• YouTube video clips
• Listen to a podcast episode
• Answer a writing prompt
• Fill out a crossword puzzle or concept map
• Create a cartoon
• Answer a question in an online voice recorder (such as vocaroo)
• Take a photograph that represents a science concept

How to grade choice boards:
It is up to you on how many tasks you want students to complete on the choice board and how you will assess them. Grading ideas could include:

• Grade for completion
• Create a rubric
• For virtual labs or online games, you can have students screenshot their high score
• Type up questions that go along with videos or podcast episodes
• Insert their answers into a Google form

Here is a preview of a choice board I created for cell organelles to give you an idea of how they work:

If you don't want to make your own, I've created choice boards for biology and earth science units. CLICK HERE to check them out!

Previously, I wrote a blog post on how powerful guest speakers can be and where to find them. I wanted to do a follow up post on how to prep your students so the experience is meaningful. Nothing is worse than having a student make an inappropriate comment or putting their head down. You can avoid any cringe-worthy situations with a little prep work.

WHAT TO DO BEFORE THE GUEST SPEAKER COMES
A day or two before the guest speaker is scheduled to come in, talk to your students about the upcoming experience. I let them know who is coming and what they plan to talk about. Have students write out 3-5 questions they want to ask the speaker on that particular topic. 

Even though you may have the best behaved class, sometimes when someone else enters the room the dynamic can change. I always remind them what appropriate behavior looks like. These behaviors would include: coming to class on time, making eye contact, being an active listener, and not asking questions the speaker has already covered (unless they need some clarification). I also remind students that guest speakers are not only coming for free on their own time, they might even be burning some sick time at their regular job to be here, so it's super important to be respectful.

Also, it's not a bad idea to prep the guest speaker on a few things via email before they come. I usually include things like:

• Background on your class- age level of your students, what they have been learning about, and what they should already know about the speaking topic.
• Any pertinent information about your school  such as where to park and check in at the office.
• I have found it to be super helpful to give them a quick teaching tip regarding wait time. Yes they are professional adults but that doesn't mean they are used to speaking to kids all day! I've found that guest speakers tend to ask students a question, wait about 2 seconds, and then answer it themselves. Let them know that your students need some processing time (or time to get the courage to talk to a stranger) and to push through that awkward silence or rephrase the question before giving them the answer. No one has ever been offended by me giving a teaching tip (you can also do this the day of the presentation before they begin).

WHAT TO DO DURING THE PRESENTATION
I've found students to be much better listeners when they have to take notes. You can decide if they should take notes on the entire presentation or just notes relating to the prepared questions they have. Either way, unless you teach upperclassmen, your kiddos need something to keep them busy and actively listening. Have them turn their notes in at the end of class for some points. You can even have them answer some exit ticket questions on the back of their notes like "what is one thing you learned from this speaker" or "what is something that impressed you about their job/background?"

Also, don't be afraid to intervene when necessary- don't let the speaker "sink or swim." Sometimes it feels like a fine line between needing to loosen the teacher reins a little and let another adult teach, while also managing your students you know so well.

If the unfortunate happens and a student misbehaves, take care of it so the speaker can continue on with their presentation. If you have a particular student you are worried about, ask the teacher next door the day prior if you can send the student over to work quietly in the event they act up. This rarely happens, but it's better to be prepared.

If you have middle school students, sometimes they have questions that might need to be rephrased. For example, you may have a student that raises their hand and asks "How much money do you make a year?" You could jump in and say "It's more polite to ask what the average salary is for someone in your industry." It's a genuine question, but you can help so it's not awkward for the speaker.


WHAT TO DO AFTER THE PRESENTATION
I always send a quick email after school that day thanking the speaker for coming. However, it's even more meaningful to have students send thank you notes. If you are 1:1 with technology, have them type up a quick thank-you email the following day. You can compile them and send them off all together. Whenever I've done this I ALWAYS get an email back from the speaker saying how happy they were to hear from the students.

Also, if the speaker does a great job, be sure to file their information away in a safe place so you can invite them back in future years! Save their name and email in a guest speaker spreadsheet so you have quick access in the future.



Have any questions I didn't cover or additional tips based on your past experiences? Leave me a comment!

It doesn't matter what age you are, glow in the dark experiments are a blast!

Did you know that tonic water glows under a black light? It has a chemical in it called "quinine" that causes it to glow. You can substitute out tonic water for regular tap water in some of your go-to experiments to make them glow! Here are a few of my favorites:

OOBLEK!
Ooblek is super fun to make when learning states of matter. Is it a solid? Is it a liquid? (It's a colloid). To make ooblek, you normally mix 1 part water to 2 parts cornstarch. Sub out tap water for tonic water and now you have a glowing non-Newtonian fluid. Around Halloween we call them "ghost guts!"

RUBBER EGG
When teaching cell membranes, many teachers do the classic rubber egg experiment. In this lab, you begin by dissolving the shell of an egg with vinegar (change out the vinegar on day 2 and continue to let it sit about 2 more days). Once your shell is dissolved you are left with the membrane of the egg sans shell. You can take it a step further and soak your rubberized egg in different liquids such as corn syrup and see what happens. This simulates osmosis and how cells swell in hypotonic solutions and shrink in hypertonic solutions.

To make your rubber egg glow, use a 50-50 mixture of vinegar and tonic water. (You could even be sneaky and add tonic water to a random few beakers from the class and freak them out by telling them they must have gotten radioactive eggs).

DIY LAVA LAMP
Want to make your own lava lamp? Fill a container with 50% tonic water and 50% vegetable oil. Turn off the lights, add your black light, drop in an alka selzer tablet, and enjoy the show! This can be done to reinforce density (layers) and chemical reactions (CO2 bubbles).

Looking for more spook-tacular Halloween science ideas? Check out this blog post!