Are the following physical or chemical changes?

1. the teeth tear off a bite of pizza:

2. the starch in the pizza crust turns to sugar:

3. muscles squeeze the chewed pizza down your esophagus:

4. in the intestines, liquids from the kidneys and pancreas mix with leftovers from the stomach:

5. water is recycled back into your body:

Is 9 correct? and can someone me with 10? it’s due tomorrow, you

Two nails have identical sizes and shapes. in one nail, 20 percent of the domains are lined up. in the other nail, 80 percent of the domains are lined up. which has stronger magnetic force? first answer gets brainliest!

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost