Dry Ice: Extremely Frozen

Everyone has fun with dry ice!  What exactly is that stuff anyway?

A french scientist discovered how to freeze carbon dioxide.  The average temperature of dry ice is -109 degrees Fahrenheit.  In 1835, Jean-Charles Thilorier learned how to sell it as little white pellets to those who needed something really cold.

Dry ice is so, SO, cold that it "sublimates", meaning it goes from a cold solid directly to a gas.  When exposed to air temperature it immediately begins to sublimate.

Sometimes dry ice will appear to look like "snow".  The tiny particles of gas are small and can be compacted into chunks or pellets, like above.  If you dropped a cube of dry ice into water it sinks.  You can make carbon dioxide a liquid, but it has to be put into a high pressure environment.  When using dry ice, the gas will sink to the floor because it is heavier than air! 

I know a lot of  people wish they could play with dry ice more and have lots of questions, so what would happen if you put dry ice in a pool?  Watch this! If you watch to the end, the guy drops an X-box in there!

Okay, one more...how about dry ice and LAVA! 

Not what I expected, but very satisfying!  Well!  Dry ice will continue to supply enjoyment and awe for years to come!

The Difference Between Heat and Temperature

Remember when you have a fever and you feel really hot and you really want to know how hot you are?

Does knowing how hot you are make you feel better?  No! In fact, you usually feel worse because you know how hot you are!  So what's the difference between heat and temperature? 

Heat and temperature are related, but they aren't exactly the same.  Heat is the total energy of the molecules crashing into each other in a substance.  That substance could be your body and the cold or flu makes your metabolism work harder, creating more heat because now you have white blood cells racing through your veins and lymph system attacking the poisons in your body. 

The temperature or thermometer helps you understand the average energy of all those molecules working to destroy those bad boys.  If your temperature is 99.7 degrees Fahrenheit, your body is working harder than normal.  Normal is 98.6 degrees Fahrenheit.  If your temperature is 104 degrees Fahrenheit, the average energy of those molecular workers is much higher than they should be and you know 1) you better get cooled off quick, 2) call the doctor and 3) take some fever-decreaser medication!

In review!  The thermometer helps you understand the average amount of heat energy in a system.   Heat equals the TOTAL energy in the system.

Got it?

Water in Space

Since scientists have been sending astronauts into space, especially to the International Space Station, they have noticed a lot of differences in how objects behave in space.  Experiments have shown that flowers smell different, moss grows in a circular fashion and fire burns in a ball shape.  Water has been very interesting to study in space. 

In space water forms a round glob that acts more like jello than water.  

Trying to get water off of a towel or out of a syringe is sometimes tough because it acts like a gel, instead of a liquid.

The reason water molecules form spheres in space is due to its amazing ability to stick together.  Water molecules are very sticky on Earth.  In space the molecules stick together even more.  On Earth, gravity pulls water into the shape of a container, like a glass, a lake, pond or pool.  In micro-gravity water creates surface tension outside any container.  Water's bonds are so strong that astronauts can play water games in space!

The water actually looks like it has "skin" on the outside.  He looks like he is "eating" water! This is surface tension. 

In space, gravity doesn't act the same as on Earth.  There are lots of interesting science on the ISS and in space because things are just a little different.  Wait, lots different!

Astronauts put a camera in a "bubble" of water...watch what happens...

 

How cool is that??

Water, Water, Everywhere!

Did you know....
It would take 800 trillion Olympic sized swimming pools of water to contain all the water in the world.

97% of all the water on Earth is salty.

Water is sticky.  Thank goodness because we have lots of water in our bodies and it helps pull blood up some of our narrow blood vessels. 

Actually water is the second most common molecule in the universe!  Hydrogen is number one.

It is believed that all the water on Earth came from comets and asteroids that collided with Earth about 4.5 billion years ago. 

Antarctic stores 10 thousand trillion tons of snow and ice.  

Hot water freezes faster than cold water...and no one really knows why....

Everywhere there is liquid on Earth, there is life.  Even if the water is boiling hot.

Leonardo DaVinci was obsessed 

with water.  He drew water endlessly and figured out a lot of science about water before anyone really thought about water. 

This is just a tiny sampling of how wonderful water is.  There are 100's of examples of amazing water facts.  We are very lucky to have this resource on our planet.

Newtonian Liquids

Ever heard of Oobleck?  The word sounds like "You-blek"....and it's possibly the most interesting substance because it can't decide if its a solid or a liquid. 

When the "substance" is sitting in a bowl and you put your finger in it, your finger will slide into the goo.  But, if you take your fingers and start putting lots of pressure on the goo, it stiffens up and acts like a solid!  What is this stuff made of?

You really need to make this stuff and play with it yourself.  It's kind of messy, but promise your parents you are responsible and will clean up every little bit!

Once you have your oobleck made, punch it, squeeze it, slowly move your fingers through it.  If you like weird things, you will love this!

This is what happens on a particle level:
There are solid particles in the mixture (cornstarch plus water).  If you stir slowly, the water continues to move between the solid particles.  If you push hard on the mixture, the water is squeezed out and you are left with only solid particles. Once you take away the pressure, the water can flow back in between the solid particles and the mixture acts fluid again.

Scientists can shake the water out with sound waves. 

Shoot objects through it.

Even try to ride bikes across it!

Check your cupboards, most households use cornstarch for thickening sauces and soups. You will need to experiment with how much cornstarch to water you will need, but that's all part of the fun!

States of Matter

Matter can exist in three different states.

Solids are defined by these characteristics:
Definite shape
Definite volume
Particles vibrate in place

Liquids have the following characteristics:
No definite shape.  Takes the shape of the container.
Has definite volume.
Particles are free to move over each other, but are still attached.

Gases have the following characteristics:

No definite shape. Takes the shape of its container.

No definite volume.

Particles move in random motion without any attraction to each other, except maybe random collisions.

If matter is tightly packed together it is very dense.

If the particles are very spread apart they are not very dense.

Those are the 3 states of matter...there is a fourth.  Plasma! 

Plasma! Super. Heated. Particles.  Saved the best for last.  

Particle Models and the States of Matter

How do particle models help us learn about atoms and molecules?  Well, 2000 years ago a smart guy in Greece, Democritus, thought, " if I cut into matter, and make smaller and smaller cuts, we will be able to find the building blocks of matter."  He was absolutely right!

There are 4 parts to the particle model theory.  They are pretty simple, here we go!

1. All matter is made of tiny particles.
2. The tiny particles are always moving.
3. The particles have spaces between them.
4. Adding heat or energy will make the tiny particles move faster.

Particles behave differently when exposed to heat.  The matter becomes more energetic and can go from a frozen state all the way to the hottest plasma if more and more heat (energy) is added to the system.

I have a question!  How does snow disappear when the temperature outside is only about 25 degrees Fahrenheit?  If you need heat to make molecules vibrate, wouldn't cold make the molecules stay frozen?

Sublimation:  when frozen objects don't melt. The molecules move fast enough that it skips the melt stage and goes to a gas.  What's up with that?

States of Matter....kind of like the "twilight zone"....

Forever and For Always, Matter

Where did matter come from?
Can we make stuff from nothing?
Can we destroy matter?
Will matter make the Universe collapse?

Antoine Lavoisier, a French chemist, created a law that still stands today.  He said..."matter is neither created nor destroyed. ... the total amount of mass and energy in the universe is constant." 

Lavoisier was a brilliant chemist that lived during the French Revolution.  He insisted that science was very good for governments and economies.  His passionate pleas for increased science caused radical rebels to throw him in jail.  He was executed by the guillotine. In 1794, Paris lost one of the greatest minds in history.

This theory of matter is still used today.  Because matter is constant in the Universe it will not be the cause of its collapse.

So where does matter come from?  There are two camps: a) God created matter, or b) the Big Bang created matter.  Both ideas, spiritual and scientific have not been proven for sure.  Some people go on to ask, "who created God?"

These questions create something called an "infinite loop".  We may never find the answer to these questions....

This leaves the last question:  Can men make new matter?  Yes.

Using a Large Hadron Collider, scientists try to force new protons into smaller atoms to try a create larger atoms.  

Scientists hope to make "universal" discoveries by shooting protons at nearly the speed of light toward each other and forcing them to crash together.  The hope is that the smallest particles will be exposed and scientists will find the key to the Big Bang = origin of our universe. 

Watch this!  Engineers and scientists working together can create great experiments with matter.  I know!  Mind blowing!