Have a question? My team and I are happy to hear your questions and get you answers! When you type a question, it shows up not only on that experiment but also here so you can easily find your answer. You'll find question boxes at the bottom of every experiment in the program.

Question: from melissarea about the Laundry Soap Crystals experiment :

It would be nice to see a little more explanation of the science involved in this experiment. How do we go from a liquid to solid state? Is this due to heating/cooling the solution? What causes the atoms to line up and solidify into a pattern? Are crystals always formed as a result of supersaturated solutions?

Question: from bac051201 about the Can Bacteria Get Sick? experiment :

My brothers and I watched a video that said if the bacteria become immune to the phages they will have to give up there immunity to the antibiotics. Plus the phages are living to so they can also adapt.

Answer:  Part 11: Astrobiology

Great question! I put one together based on your feedback - will you let me know what you think? You'll find it here: https://www.sciencelearningspace2.com/grade-levels/high-school/biology-overview-course/ in Step 2.

Answer:  Atmospheres

Great questions! 1. Substances are USUALLY more dense the colder they become. Water is the most dense at 4 deg C (otherwise ice would sink and that's a problem if you're a glacier), not zero. Venus' atmospheric pressure is 90atm, and the Earth is only 1 atm, so that's a big difference. There's a lot more pressure in the atm on Venus than on the Earth. Venus is also the hottest planet. Sunlight passes through the cloud layers and gets trapped by that thick atmosphere, so the heat builds up to really high temperatures. 2. Temp and pressure are related, but they are also two different things. Did you get to the experiment about the ping pong balls representing the energy of the molecules? Its in the Ideal Gas section of the High School level in Chemistry. Think of a room full of ping pong balls bouncing all around on their own off the floor, ceiling and walls. Now make them bounce around twice as fast (raise the temperature) - what change does the wall feel? More hits per second, right? That's pressure. As temperature increases with gases, the pressure will also increase. If you make the room smaller and hold the temperature constant, now the balls hit the walls more frequently again, making the pressure and temperature go up with a volume decrease. You can independently change one (temperature, pressure, and volume) and watch how they affect the others. If heat rises, why are mountaintops usually cold? The top floor of a house is usually warmer than the downstairs, right? As air rises, the pressure decreases, which lowers the temperature. As warm air rises, it cools off due to lower pressure. Also down near the surface of the earth, heat gets trapped by an insulating layer of air, and the higher up you go, the atmosphere loses heat faster than it is warmed by the sun (or ground) so it also gets colder. Hope this helps! Aurora

Answer:  How to use a Digital MultiMeter

Look at one of the starting experiments - "Basic Circuits" - do you see it? There are complete instructions.

Answer:  How to use a Digital MultiMeter

Me too! A DMM is super-useful!

Answer:  Newton's First Law of Motion

Thanks for the feedback! I did - you'll find it at the start of each section as a massive download.

Answer:  Wireless FM Transmitter (the 'Bug')

Send me an email with images of your project so we can help. I apologize for not getting to your question right away - I had trouble my computer, and had to get a new one and this is only the second day I've had access! [email protected]

Answer:  Bernoulli’s Principle

Excellent question! What happens if you try it? (smile!)

Answer:  Cobalt Colors

No, you need cobalt chloride. Sodium chloride will just give you salt water!

Answer:  Cobalt Colors

I always wear gloves when handling chemicals - it's a good practice to have when doing chemistry!

Answer:  Cool Blue Light Chemiluminescence Experiment

Some people have a skin sensitivity to the chemicals inside, so I would use soap and water.

Answer:  Corny Slime

It will keep in the fridge or the freezer!

Question: from cahira about the Part 11: Astrobiology experiment :

Hi! Is there a syllabus or guide that shows how many videos there are in this Biology overview? It would help with planning to also see an overview. Thank you!

Question: from AmyCrafton about the Atmospheres experiment :

Question 1: Cold air/liquid is more dense and sinks because the molecules are closer together. Warm air/liquid rises because the molecules are further apart thus less dense. Is this correct? It is also my understanding that because Venus's atmosphere is more dense it is one of the hottest planets. Does this information contradict my previous statement? Question 2: Venus Atmosphere is Dense. I know from experience that a thicker i.e denser blanket retains more heat. Cold air is also dense, yet it is cold. Why is this? Thank you. Amy, Avery and Julia C

Question: from cmsobleo about the How to use a Digital MultiMeter experiment :

I LOVE THIS

Question: from cmsobleo about the How to use a Digital MultiMeter experiment :

how do you hook up a LED

Question: from zannec about the Newton's First Law of Motion experiment :

The all in one download file is definitely very helpful. It helps us orientate ourselves through the sections too. Please make one for all the topics.

Question: from trganzhorn about the Wireless FM Transmitter (the 'Bug') experiment :

Hi, I have tried to tune the kit and it does not work. I have tried everything I can think of. What should I do?

Question: from heatherjma about the States of Matter experiment :

Tana Bradley The select substance is called Bose–Einstein condensate (BEC). it happens when a very select number of atoms clump together at almost absolute zero degrees (in Kelvin). The temperature of space is three degrees Kelvin.

Question: from heatherjma about the Bernoulli’s Principle experiment :

Would the ping pong fly out at your face if you blew directly on it from above?

Question: from tsyed about the Cobalt Colors experiment :

Also, will sodium chloride work?

Question: from tsyed about the Cobalt Colors experiment :

Is this stuff safe to touch with your hands?

Question: from tsyed about the Cool Blue Light Chemiluminescence Experiment experiment :

One time I had a glow stick and it broke onto my hands. is that dangerous?

Question: from mad_tea_party about the Gravity experiment :

Hi! A couple questions: For practice problem 7 on 1-D Kinematics Student worksheet, is the unit conversion from hours to seconds correct? I get 5 seconds equals 0.0014 hours, but the solution shows 0.002 hours. For problem 8 on 1-D Kinematics Student worksheet, you define the max acceleration but not the max deceleration. My Dad said to assume they are the same. Is that right? He said that looking at your solution, it appears that you are assuming the train is already at Vi 1.6 km out. He thinks that if acceleration and deceleration are the same rate, I should divide the distance in half to solve for Vmax and then double that time for the overall elapsed time? Is he correct? Thanks! And also thanks for making physics fun and understandable :) Bri

Question: from tsyed about the Corny Slime experiment :

How do you store it if you wanted to keep it?

Answer:  Electron configuration

Calcium has 20 electrons, and these fill starting at the lowest possible/available energy before filling higher levels (1s before 2s): B (Z=5) configuration: 1s2 2s2 2p1 C (Z=6) configuration: 1s2 2s2 2p2 N (Z=7) configuration: 1s2 2s2 2p3 O (Z=8) configuration: 1s2 2s2 2p4 F (Z=9) configuration: 1s2 2s2 2p5 Things start to get a little unexpected as we go higher. For example, 4s is filled before 3d. As the energy of the 3d is higher than 4s, the last two electrons go to 4s, not 3d. It should be 2, 8, 8, 2 and not 2, 8, 10. Afbau’s principle states that electrons are added to orbitals as protons are added to an atom. When you write down an atom's configuration, you start with the lowest energy level and add electrons to higher sublevels until you reach the required number of electrons. Energy levels are filled from the bottom up. Beyond the first 20 elements, you need to look at other things that come into play when determining the energy levels/electron placements.

Answer:  Temperature and Thermometers

Yes thanks for letting us know. "Temperature and Thermometers" is the first lesson in the main unit of "Chemical Bonding" so it takes you straight there.

Answer:  Periodic Table

Here's one that you can use: http://science.widener.edu/~svanbram/ptable_6.pdf And here is an interactive one: https://www.ptable.com/

Answer:  Bubble Experiments

Oh no! I'll have Tonya connect with you right away.

Question: from marknkatie about the Bubble Experiments experiment :

We can’t access this lesson at all for my 5th grader. But, even so, we have an advanced membership and should have access to the entire site. Please help?

Question: from joannmiller00 about the Temperature and Thermometers experiment :

Chemical Bonding links to this lesson instead: Temperature and Thermometers

Question: from joannmiller00 about the Electron configuration experiment :

I have a diagram with a Calcium atom diagram and the shells are listed from nucleus to the third shell with the electrons listed in the respective order 2,8,8,2. Is this just unique or was it a typo that should have read the electron numbers: 2,8,10?

Question: from joannmiller00 about the Periodic Table experiment :

Is there periodic table that I can print out that match the colors chart you used in this lesson?

Question: from bac051201 about the Tracking Traits experiment :

Ok , thanks

Answer:  Newton's Second Law of Motion

The "why" is determined by observing "what happens if...". For example, when you first drop a single ball, why does it bounce at all and not stick to the floor? It's a collision between the ball and the floor. You can tell it's an inelastic collision because the ball doesn't bounce as high as the drop height, and gets lower and lower with every bounce. Some of the ball's energy went was lost to heat and sound (did you hear it bounce?) Now watch what happens when you drop the second ball by itself - notice how high it goes with the first bounce. Now drop the two together, one on top of the other and notice the height of each one as it bounces. Did you notice one went a LOT further, and the other hardly at all? That's the momentum being conserved and the energy transferring from one object to the other. The math involved with proving that the energy must transfer is actually quite involved, which is why we're looking at actually WHAT happened and figuring out what's going on through observation. You'd actually look at the forces involved before, during and after the collision in order to map out the entire system. Does that help?

Answer:  Tracking Traits

Although scientists know a lot about the genetics of different eye colors, one they don't have a lot of distinctions about is the difference between gray and blue. There are two things that could determine gray eye color: the amount of melanin (pigment in the eye) made and the density of the proteins in the stroma, both of which can be determined by genetics. It's not really well understood, but different people can have different versions of this gene, and some versions are better at making melanin than others. There's not any name for it, like "hazel", just "gray" or "blue".

Question: from bac051201 about the Tracking Traits experiment :

What is it called when you have a mix between blue and gray for eye color.

Question: from Koachkaren about the Newton's Second Law of Motion experiment :

Thanks for the feedback! I'm still missing something as to the "why" of the transfer of energy. I see the transfer of energy and conservation of momentum. I understand the concept in general, but my missing link is understanding why the bottom ball has a need to transfer the energy. Why don't both balls just bounce up? Does it have something to do with the bottom ball actually being stopped whereas the top ball only changes direction of motion?? It's driving me crazy trying to figure out what I'm missing.

Answer:  Constant Acceleration

You can just use the PDF file worksheet - it's about the some. The main difference is that in the xls spreadsheet, I've already pt in the equations with sample data. If you really want to look at it, try a friend's computer? I know Google Sheets is popular now, but it simply isn't powerful enough for most scientists and engineers to use when they start plotting their data and doing graphs and statistical analysis.

Question: from michelle_s about the Constant Acceleration experiment :

I do not have the excel program to open or print off some of the printouts. Is there another way?

Answer:  Newton's Second Law of Motion

Oh, my... it sounds like fun and educational! Yes, scientists DO need to wear goggles!!! I would do at least 3 trials so make sure you've got repeatable results, especially if one of them doesn't make sense or is different than you expect. I would also weigh all three, because it's the mass change you're most interested in. If you want to take it a step further, you can calculate your momentum both before and after and see if they are about the same. Momentum = mass x velocity For calculating initial velocity of the top ball after collision, if you can get the top ball to go near-vertical in its flight, notice how high it went and that's your "h" in the following equation (make sure your number for h is either in feet or meters and then choose the appropriate value for "g"): v = sqrt (2 x g x h) where g = 9.81 m/s^2 or 32.2 ft/s^2 (sqrt = square root) Now you can find out exactly how much momentum your system had both before and after, and you should have the same number! I like the idea of trying multiple balls - that's exactly how this program was intended to be used - great job!!!

Answer:  Newton's Second Law of Motion

Great question! Momentum conservation is really a statement of Newton's 3rd law of motion. If you notice when the balls drop, they have a certain momentum (mass x velocity) which is equal to the momentum of the top ball after the collision (the mass doesn't change, so you see a significant increase in the velocity after impact). Momentum conservation is one of the basic laws of physics.

Answer:  Detecting the Gravitational Field

Oh, no! Thanks for letting us know - I'll send this right over to our tech team and get them to fix it. Thanks for helping us fix all the bugs!!

Question: from laurel9987 about the Detecting the Gravitational Field experiment :

We have been trying to use the new learning space but it isn't giving us access to any of the mechanics lesson. Just giving feedback to help with the site :)

Question: from Koachkaren about the Newton's Second Law of Motion experiment :

HA! Next observation and question: We are using 3 balls and observing the differences. Ball 1: small, solid, bouncy ball (~1inch diameter) Ball 2: medium, air filled bouncy ball (~4 inch diameter) Ball 3: Size 5 soccer ball (~10 inch diameter) Experiment 1: Ball 1 over Ball 2. Sweet spot is maybe 8 inches above ground so that Ball 1 doesn't have time to roll to one side. Observation: Ball 2 bounces very slightly. Ball 1 shoots off. PERFECT! Experiment 2: Ball 2 over Ball 3. Same height. Ball 3 stops dead and Ball 2 shoots off way high. AWESOME! Experiment 3: Ball 1 over Ball 3. All same height. Ball 1 only bounces slightly higher than it would on it's own. Ball 3 retains some of it's own momentum and bounces more. We know it either has to do with materials of the balls or, more likely, the discrepancy in ball size. So, we thought maybe of the energy that is returned to the balls after colliding with the floor, only the energy that is in the direct spot that ball 1 is in is being transferred. All other energy is still dissipating through the Ball 3. ??? Experiment 4: My husband and son decided to venture off into the great wide unknown and try the experiment with all 3 balls stacked. 1st time: great results. Ball one flew off! 2nd time: My 8 yo son had to help hold the balls in place before dropping and then had the painful lesson of learning why scientists usually wear goggles... Smacked him right in the eye! Poor kid is icing it now. :'( But, no worries. He looks fine.

Question: from Koachkaren about the Newton's Second Law of Motion experiment :

Hi Aurora, We are having fun experimenting with various heights from which to drop the balls in order to make the top ball bounce up rather than have time to roll to the side a bit and fly out in another direction. The thing that we're wondering is, why is the momentum transferring in the first place? Why is it that the bottom ball isn't bouncing and instead is transferring energy to the top ball?

Question: from anita_fair about the Extracting DNA in your Kitchen experiment :

"Thank you for your great answer!" -Gabriel

Question: from crystal_ashby about the Special Science Teleclass: Thermodynamics experiment :

thank's we will try it

Answer:  Introduction to Creating a Homemade Weather Station

Something doesn't sound right - I'll have Tonya connect with you right away.

Answer:  Special Science Teleclass: Thermodynamics

This is one of the trickier experiments! The sodium acetate version is easier, just FYI. What happens if you leave a thermometer in the bowl to monitor the temperature? It should register about 30 degrees - if it's much higher it will not work. (Also - did you stick it in the freezer for 20-30 minu after an overnight stay in the fridge?)

Question: from shannen_e about the Introduction to Creating a Homemade Weather Station experiment :

I also can't see all the content for this page as it says it's high school material.

Question: from crystal_ashby about the Special Science Teleclass: Thermodynamics experiment :

We've tried the ice bowl experiment both ways and do not get the expected results. Any ideas on what we're doing wrong?

Answer:  Genie in a Bottle

Awesome! Great job!

Answer:  Hot Air Balloon

Because the experiment is kind of short, it will work if the opening is only the size of the hair dryer's nozzle. Warm air rises, which is what we see happening when you shut off the hair dryer!

Answer:  How to Use a Microscope: Optics, Observing, and Drawing Techniques

I'll have Tonya connect with you right away!

Answer:  Special Science Teleclass: Black Holes

The largest supermassive black hole appears to be that of M87 which is at a distance of 53.5 million light-years from us. You can learn more about it here: https://en.wikipedia.org/wiki/Supermassive_black_hole

Answer:  Shopping List for Unit 20

A lot of these items you probably already have around the house. For the geology unit, don't feel like you have to go out and purchase a bunch of rocks! The ones I use in the videos are from GeoIndustries and there's order links if you really want those particular ones. I would recommend the "Geology Field Trip bag" and the Washington Student Pack, both are under $10. Does that help?

Question: from dora_0419 about the Genie in a Bottle experiment :

Aurora I loved this experiment it worked great you were right about doing it over the bathtub I did it over the bathtub and if glad after holding it perfectly for a while i'm moved my arm a little and it started to poor out so i just let it fall and it left a big mess but it was fun.

Question: from dora_0419 about the Hot Air Balloon experiment :

How does it stay up if it has an opening in it at the bottom?

Question: from kkeitel1 about the How to Use a Microscope: Optics, Observing, and Drawing Techniques experiment :

Hi, I would like access to all of the unit for the 6th Grade. I am unable to view the videos. Thanks Kimberly

Question: from klundahl about the Special Science Teleclass: Black Holes experiment :

how big is the biggest black hole

Question: from betty_shep about the Shopping List for Unit 20 experiment :

where do we find the supply kits to purchase for each of these lessons? Are they more affordable than filling my Amazon cart?? LOL

Answer:  Wind Turbine

Here's something you might like: https://www.eia.gov/energyexplained/renewable-sources/ It shows you the energy the US uses. This is a chart of the Renewable energy consumption: https://www.eia.gov/renewable/ And here's one that compares it: https://ourworldindata.org/renewable-energy

Answer:  Hovercraft Project

That's a great idea - and actually something that engineers are working on. Solar powered aircraft are still in the development phase, but you can learn more about it here: https://en.wikipedia.org/wiki/Solar_Impulse Because solar panels are so heavy for the amount of power they generate, my best advice is for you to hold the solar cell in your hand with wires running to the hovercraft, or have the hovercraft pull it along behind it in a little cart of some kind. Thank you for your kind words!

Answer:  Extracting DNA in your Kitchen

Hi Gabriel! Yes you can extract DNA from any living thing. Spiderman got his abilities from being bitten by a radioactive spider. Actually, Spiderman got his abilities from a writer who invented a cool story. There's been a lot of things invented AFTER writers think them up (Star Trek is a great example of this), however there are some things that are still not within our reach (light sabers from Star Wars, warp drive and transporting through teleporters). Keep thinking up cool things and writing down your ideas so you can design experiments around them!

Question: from tsyed about the Food Dye Currents experiment :

Do you know where the worksheets for this experiment is?

Question: from mguske about the Wind Turbine experiment :

What kind of alternative (renewable, is there a difference) energy is the most efficient from a cost/benefit analysis?

Question: from mguske about the Hovercraft Project experiment :

I want to wire a small solar panel to the hovercraft, how would I do that? Also I was wondering if there is a equation for the weight of a power source, the power output, and the power needed? This is an amazing course thank you!!!

Question: from anita_fair about the Extracting DNA in your Kitchen experiment :

"We tried the experiment with pear and with pumpkin and took pictures with our microscope. Would it work with spiders? I want to learn how to extract spider DNA so I can be Spiderman." -Gabriel, age 6

Answer:  How to Use a Microscope: Optics, Observing, and Drawing Techniques

Hi Andie! That's actually a great idea. I just put together information on how to become a pilot. I think I can put something similar together for nursing school. I'll let you know when it's posted!

Answer:  Onion Mitosis

Yes eosin dye is used for staining in biology, but it stains a different part of the cell than iodine does. Iodine stains the carbohydrates brown or blue/black, and eosin Y stains the cytoplasm pink. Both are used on cells. You can substitute eosin dye for carmine and "congo red".

Question: from robertdangelo about the How to Use a Microscope: Optics, Observing, and Drawing Techniques experiment :

Hey Aurora, it's Andie. I am trying to effectively teach biology to myself. I want to be a nurse when I'm older, and want to learn biology ahead of time, so that I don't have to listen to that one boring professor who bores everybody to death; because, I already know what he's saying. I want to use my amazing binocular microscope, but I don't know what to look at. I'm striving to obtain real knowledge, not just look at cells and say "Oh, neat!", without really knowing what it is. Since you are a scientist yourself, I was hoping maybe you could give me some advise. I have looked at some things that I found growing in that cup that I forgot to wash, but I don't think that's enough to get into nursing school. If you could send me a list of things that I could look at, and learn from, that would be great. Thank you, Andie D'

Question: from bac051201 about the Onion Mitosis experiment :

Miss Aurora, I have eosin dye can I use that instead of iodine?

Answer:  Chemical Fingerprinting

I know - originally it was taken off the market because it was dyeing all the other recyclables and making them un-recyclable. And then they fixed the problem and put it back on the market, but teachers had found ways around it during that 5 year absence so it's not selling quite as well as it used to (they learned how to make their own using turmeric). I can send you a few sheets, free of charge for being a member. Send me a private email with your mailing address and make a note of our conversation and what you need, and my team will get it to you! Here's the link on making it yourself if you're interested: http://blog.teachersource.com/2014/02/05/make-goldenrod-paper/

Answer:  Cell Walls of Cotton

That's amazing - great job!!!

Answer:  Celery Stalk Water Race

Wow - cool! Before I answer, tell me what you think happened!!

Question: from asierra0328 about the Chemical Fingerprinting experiment :

Hi Aurora, is there any way we can get a few sheets of the golden rod paper? I will definitely pay. :D It's very difficult to find.

Question: from bac051201 about the Cell Walls of Cotton experiment :

I fit 37! 37! In a half-pint of water!

Question: from bac051201 about the Celery Stalk Water Race experiment :

Ms. Aurora, I tried to make my celery stalk purple, so I combined equal portions of red and blue food coloring into my water. after this, I left the celery out overnight. but the celery separated the red dye from the blue, and left me with blue water! could you explain why this happened?

Answer:  Lie Detector Circuit

The base of the PNP is very sensitive (it's an amplifier transitor) and its measuring tiny fluctuations in resistance between two probes. When someone lies, their skin tends to become more moist (more conductive) which turns the PNP on which changes the tone in the speaker.

Answer:  Making Fossils

I've sent you a private email answering your question.

Answer:  BRAND NEW Supercharged Science Website for e-Science!!!

Oh no! Can you send me a personal email ([email protected]) with the url you're on and a screenshot so we can work out the bugs?

Answer:  Invisible Writing

You can probably make out what you've written if you use sunlight and have a good eye!

Answer:  Gravimetric Calculations

Yes that's right. Just to be clear: When you add up all the different molar masses Ca = 40 C = 12 O3 = 16 x 3 = 48 You get 100. And 40/100 = 40%.

Question: from wendy0gors about the Making Fossils experiment :

Do you have a good video or reference to show the kids how fossils are formed in the natural world? Like how a tree seems to turn to rock?

Question: from tsyed about the Lie Detector Circuit experiment :

how does it detect lying? doesn't it make noise if you touch and your not lying?

Question: from mottfamily8 about the BRAND NEW Supercharged Science Website for e-Science!!! experiment :

I can't get into the lessons on the new website. It tells me I have to log in and then takes me to a page that says"this page does not exist". Are the experiements and lessons the same on the old website and the new one?

Question: from tsyed about the Invisible Writing experiment :

could you use the sun? a lot of sunlight will be reflected off the paper?

Question: from ebrice about the Gravimetric Calculations experiment :

My mistake, I just watched the video and missed the part about it being an IMPURE sample. If you have PURE CaCO3, would the percent by weight of Calcium be 40%?

Answer:  Constant Acceleration

Hi there, I've sent you a private email that has additional information that I hope is helpful. Let me know if you didn't get it. Aurora

Answer:  Special Science Teleclass: Black Holes

The largest supermassive black hole appears to be that of M87 at a distance of 53.5 million light-years. You can learn more about it here: https://en.wikipedia.org/wiki/Supermassive_black_hole

Question: from marknkatie about the Hidden Carbon Dioxide experiment :

Thank you for your ideas! No matter how we tried, we simply couldn’t measure the co2 by pouring it onto the scale. However, it worked beautifully by filling balloons, one with co2 and the other with air. And....we had so much fun dousing candles that we used up a half gallon of vinegar in one sitting! Point was proven!! I so appreciate your help!

Question: from saturn about the Special Science Teleclass: Black Holes experiment :

what is the BIGGEST BLACK HOLE!!!!!!!!!!!!!!!!

Question: from tsyed about the Humming Balloon experiment :

I tried my nut wasn't sharp. I think it popped cause of friction. anyway I like it and I made it again.

Question: from tsyed about the Humming Balloon experiment :

I really liked this experiment! I spun the nuts so fast my balloon popped!! So cool. Thanks.

Question: from jackson119 about the Constant Acceleration experiment :

We are having a lot of difficulty figuring this program out. We've done the driveway races but can't figure out the worksheet. Our average distances were 18" at 1 sec, 45" at 2 sec and 106" at 3 sec. We graphed those. Then it says to square the time and take half of it so we got .5 sec, 2 sec. and 4.5 sec. What do you mean by "what is left will be your acceleration?" How do we graph the results of our modified time? How are we supposed to know the distances of those times? And the second question in the following exercises part says to calculate the slope of the line but doesn't explain how. Also, there was a link to "Student worksheet and exercises" and then it said advanced students should download "Driveway Races Lab" What is meant by advanced students? Is that for AP physics? Is this course all AP? I feel like we are so lost already and we're just in the intro lesson. Was there a prerequisite class that we needed before this one? Please help!

Answer:  Gravimetric Calculations

Hi there! Tell me more about what you're asking - I am not quite understanding your question. The principle behind this technique is that the mass of the ion in a pure compound can be found and used to find the mass % of the same ion of an unpure compound if you know how much of the unpure substance you have. You must completely precipitate it and filter it in order for this to work.

Answer:  Cool Milk Trick

Try both - what happens?

Answer:  Cool Milk Trick

Leave the Chlorox and Windex on the shelf where they belong - don't just randomly mix up chemicals, because you will not always know what invisible (and possibly dangerous) gases will be created. You can add ice or freeze the bowl first and then try it...?