Physical and Chemical Changes! Wow! How... fun...?

Okay... more homework problems... I don't like chemistry at all (sorry eveanne1221) so this is just heck (if you're in the 6th grade).



First, we were supposed to look at the different examples and then tell if they were physical or chemical changes. Then, the worksheet doesn't tell us we have too but my teacher does, we have to tell why.



Here is what I have:



Rusting of Iron: Chemical Change: Unexpected and irreversible color change.

Breaking of tree limb: Physical: Change in shape.

Cutting Paper: Chemical: Change in shape.

Action of Yeast in Breadmaking: Chemical?: ?

Souring of Milk: Chemical?: ?

Wadding up Sheet of Paper: Physical: Change of Shape.

Erasing a Pencil Mark: Physical?: Change of Color?.

Freezing Water: Physical: Change in State.

Boiling Water: Chemical/Physical?: Heat given off/Change in state?.

Salting the ice on a Sidewalk: Chemical?: ?.

Action of Baking a Cake: Chemical: A Solid is Formed.

Bending a Metal Wire: Physical: Change in Shape.

Etching Glass with Acid: Chemical?: ?

Formation of Stalagmites in a Cave: Chemical?: ?

Fertilizing a Lawn: Chemical?: ?

Crushing Ice in a Blender: Physical: Change of Shape.

Evaporation of Water in a Lake: Physical?: Change of Shape?.

Chewing Foods: Physical? Change of Shape?

Burning Gasoline in a Car Engine: Chemical? Heat given off?

Burning Logs in a Fireplace: Chemical: Unexpected and Irreversible Color Change.

Toasting Marshmallows over a Campfire: Chemical: Unexpected and Irreversible Color Change.

Adding Bleach to a Washer of Clothes: Chemical?: ?

Slicing a Block of Cheese: Physical: Change of Shape.



WOW! WHAT FUN! ...(not)



But anyway, there are a few different reasons why, you just have to use one of the main ones.



As you can see, I'm pretty clueless...



You don't have to fill them all in yourself, just a few will help me.



First Answer (with reasonable answers) will get best right away!Physical and Chemical Changes! Wow! How... fun...?
Cutting Paper: Physical: Change in shape