Hello and welcome to my entry for the first SteemStem Science fair competition!
So, in this project I am gonna expand a bit a topic my good friend 
These were some really hard experiments to perform so I asked her trolls to come and lend a hand and they accepted! Thanks trolls, it would have been impossible without you!
Are you ready for some science? Let's do this!
Question 1 - Does Air Have Mass?
The materials we need for this experiment are:
- 2 balloons
- A string and a straw (or a scale if you want to be 100 % precise)
- A pair of functional lungs
So, first we make our scale (with the straw and string) and hang the balloons. What you see below is a high precision instrument, trust me they have the same weight:
Now we remove one of the balloons from our high precision scale, blow it and hang it again:
Tadah! What you see is proof that air has mass! At least... the air that comes out of your lungs! Don't believe me? Here's what happens after you pop the balloon (and re-attach all the pieces that flew away):
Question 2 - Does air take space?
That's a really tough question so we are gonna need to do a couple of experiments for this one:
Experiment 1. - Crushing the bottle
For this experiment we are gonna need a plastic bottle. We take the cap off and try to squeeze it. It might look easy, but that's because I am freakisingly super strong:
Now we do the same but with the cap on. Impossible, even for a demigod like me:
It's obvious, something in the second video is resisting my inhumane power! Could it be that the air inside it actually takes space? Probably yeah! When the cap is off, there is a point of release where it can get out. But when it's on, there is nowhere to go!
However, we can notice in the second video that I manage to somehow (temporarily) compress the bottle, suggesting that the air takes space, but the space that it takes can be compressed.
Now to the second experiment
Experiment 2 - Blowing a balloon inside a bottle (I couldn't come up with a better title, ok?)
For this one we are gonna need a plastic bottle, a balloon and a troll to drill a small hole at the bottom of the balloon:
So first, we try to blow the balloon without covering the hole:
Success!
Miserable fail! The air has nowhere to go and doesn't let us blow the balloon!
Note: Lungs provided by
Experiment No 3 - Pushing the cap underwater using only air
Want more proof the air actually takes space? Look me push a cap underwater with the help of it:
The non-believers will say it's water or something pushing the cap.. Really? Explain me then... why doesn't this piece of toilet paper get wet? There are only two possible explanations: a) magic b) the air takes space! Take your pick!
Exploring other properties of air!
Ok, now we know air has mass and it takes space. Let's do two more experiments to find more about it.
Experiment 1 - Bottle in the fridge
We take our bottle, put the cap on and place it in the fridge for 10-20 minutes. When you take it out you will notice that there is some water in the interior of the walls! Where did that come out? The bottle was closed!
Hmmm... Maybe there is water in the air? And for some reason it's only visible when it gets cold? I have the answer for you and you can trust me, I am a scientist. Yes, there is water in the air but in the form of gas! Once cold it turns into liquid!
Experiment 2 - Underwater fire that goes off for no apparent reason
For this experiment we are gonna push a floating candle (instead of a cap) and see what happens! (sorry for the bad video quality):
So, we see the fire burns strong for a few seconds but then it goes off for some reason!
Obviously, it's not because water gets in, we know that from the toilet-paper experiment.. This suggest that the air is burned or something. Or maybe the air has something inside it that the fire needs to stay alive!
Unfortunately nobody knows the answer to this riddle. Big scientific minds like Albert Einstein, Nikola Tesla, Niels Bohr and Rocky Balboa have tried to come up with an answer but to no avail! Maybe it's magic after all!
What we learned?
Here's a brief overview of what we learned today:
- Air has mass
- Air takes up space
- Air has water inside
- Air has something inside that get's burned (oxygen)
So that's all the with the hardcore science for today! Hope you enjoyed my entry, I know I did. See ya!