Peter, who lived 200 years ago, had a house with no rats in it. One day, his wife heard some scurrying around on his straw roof. He went up and guess what he
found? A rat's nest. Peter was really smart--where did he think the new rats came
from? Well 200 years ago, people believed that part of the straw roof somehow
turned into rats. Why would Peter, even though he was very intelligent, accept this
idea?
We're all really smart, but its not like we're the smartest people in the world. We all know that it takes a momma rat and daddy rat to make some baby rats.
This is because we understand something called the cell theory, because the cell theory is just part of our culture now. It's something a lot of our behaviors and
other ideas are based.
1. All living things are made of cells
2. Cells come from other cells
3. Cells are the smallest unit of life

1. Using two parts of the cell theory, explain to Peter why these two parts show
that the straw roof did not turn into the rats.
2. What do we mean when we say 'The cell is the smallest unit of life? Explain as if
you were talking to Peter, who has no idea about cells.

Is a measure of the resistance to flow. a high liquid has a high resistance to flow and flows slowly. the ancients thought everything in the world was made of 4 we now know that there are 94 naturally occurring and scientists have created another 24 i am certain they will create even more. honey flows slowly because it has a high to flowing. a can be separated by physical means because it contains more than one pure substance and 2 pure substances are not chemically bonded to each other. a cannot be separated by physical means. all matter is made up of all elements are with the same number of protons. if it is just a single or many bonded together, if all of them have the same number of protons, it is an element. in a piece of pure iron metal, all the are joined together, that piece of iron metal is called elemental iron. a single of iron is called elemental iron. a mixture has differences from place to place. we might need a microscope to see them or they might be obvious to the unaided eye. there are surfaces separating it into different phases. a mixture is the same everywhere. it is uniform. there are no surfaces separating it into different phases. if different kinds of atoms (different elements) are bonded together by their electrons, it is called a there are physical means of to isolate the different pure substances in a mixture and there are chemical means of to isolate the different elements in a compound. 1. element 2. compound 3. mixture 4. heterogeneous 5. homogeneous 6. pure substance 7. atoms 8. separation 9. viscosity 10. resistance