What are Physical & Chemical Changes?

Objective - To distinguish between physical & chemical changes in matter.

A physical change is a type of change in which the form of matter is altered but one substance is not transformed into another. Examples of physical changes are boiling, melting, freezing, and shredding.                                                                                              

 
A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting.

                   

Did you know...  mass, weight, volume and density are physical properties! 

 
Can you guess what the changes are by dissolving 
Alka Seltzer in water
...is it a chemical or physical change?

 




 The Students jot down quick notes to share with others in their group or class.
(*Good note-taking improves your active listening, comprehension of material, and retention.)

Popping POP(corn)!!!

What Makes Popcorn Pop?

Inside each kernel of popcorn is a tiny droplet of water surrounded by a hard shell called a hull. As the popcorn is heated, the water turns into steam, which builds pressure 
inside the kernel. 

When the hull can no longer contain the pressure — POP! — the kernel explodes and a fluffy new piece of popcorn is born.

Did you know... Popcorn needs between 13.5-14% moisture to pop.

Why did my popcorn burn and not pop?  

Popcorn pops because the water vapor inside them increases pressure enough to rupture the hull. So it really comes down to two possibilities. Your popcorn doesn't have enough moisture to pop, or it isn't getting hot enough. Most likely it's the moisture level.

As Scientist we learned that popping popcorn is not a chemical reaction. 
It is a physical reaction. All that is changed is the appearance of the popcorn kernel.

How can MATTER be Measured?

Students will be measuring, using nonstandard/standard units and metrics measurements, including meters tape and trundle wheel.

Students first predicted the length of your desk in spans. 

How do you think the measurements you and your classmates make will compare? 





Volume measures how much space something takes up.