1. The oils in peanut butter are made up of .

2. All samples of the same type of oil will have the same .

3. Materials are considered different substances if they have different or of atoms.

4. How do the particles in a liquid compare to the particles of that substance when it is a solid?

• Liquids typically have particles that are further apart than solids
• Liquids typically have particles that are closer together than solids
• Liquids typically have particles that are smaller in size than solids.
• Liquids typically have particles that are larger in size than solids.

5. This peanut butter is made up of .

6. What determines the properties of peanut butter?

• the type of molecules peanut butter is made of
• the type of food peanut butter is
• the type of peanut butter it is
• the processes that the turned peanuts into peanut butter

7. Refer to figure A. Which of the following describes a difference between the structures of saturated and unsaturated fat?

• The molecules have a different number of atoms
• The molecules are made of different atoms
• The molecules have different masses and sizes
• The molecules have a different shape caused by a different bond

8. What is the difference between an element, like oxygen (O2), and a compound, like water (H2O)?

• Oxygen is made up of molecules and water is made up of elements.
• Oxygen is made of only one atom, while water is made up of multiple atoms.
• Oxygen is made up of only one type of atom, while water is made up of more than one type of atom.
• Oxygen is made of only one molecule, while water is made up of multiple molecules.

9. Why is it helpful to create models to show differences in molecules

• A model shows less details than what is visible on a large scale.
• A model can clearly show the differences that are too small to view on a large scale.
• A model can show differences that are predicted to be true but no one will ever know for sure.
• A model shows differences in molecules that are too large to see with our eyes.

10. Which property is caused by the differences in molecular structure of the saturated and unsaturated fats in figure A?

• Mass
• Reactivity
• Solubility in water
• State of matter/Density

11. A classmate has a model kit that contains different colored spheres and connector pieces that can be used to create molecules. How will the model they construct of unsaturated fat compare to the ones in figure A?

• The spheres will all be the same color to replace the letters and the connector pieces will replace the double lines between atoms.
• A different color sphere will replace each type of letter, and each sphere will have the same number of connector pieces attached to it.
• The connector pieces will replace each type of letter and a different colored sphere will replace the single and double lines.
• A different color sphere will replace each type of letter and the connector pieces will replace the lines between atoms.

12. Bo asks a classmate how they can tell from the model in figure A that the fats in peanut butter are molecules and not atoms. What is the best answer to this question?

• The atoms are all bonded together to form one connected structure
• The atoms are arranged in a long line
• The atoms are all the same element bonded together
• The atoms are all bonded to the same central atom

13. Is it possible to observe what is different about the saturated and unsaturated fat molecules by looking at a jar of peanut butter?

• Yes, if you look closely at the layers when peanut butter separates you can see the differences in the shape of the molecules.
• No, the molecules are too small to see with our eyes, but we can observe the different bulk scale properties, like state of matter, caused by the difference in structure.
• No, the difference is so small it can’t be seen with our eyes or on a bulk scale level.
• Yes, anything that has different bulk scale properties, like the state of matter, can also be observed with our eyes at the molecular level.

14. Sam noticed the ingredient label on his peanut butter contained peanuts and less than 1% salt (NaCl). He wants to add in salt to his model. Which of the following describes how he could model salt?

• Have an atom of Na bonded to an atom of Cl and then the Cl bonded to the oil molecules in the peanut butter.
• Have one atom of Na bonded to one atom of Cl to form a compound that is near the other molecules in the peanut butter.
• Have atoms of Na and atoms of Cl distributed throughout the other molecules in the peanut butter.
• Have atoms of Na and atoms of Cl bonded to the ends of the oil molecules in the peanut butter.

15. One of your friends was surprised to learn that the liquid layer in peanut butter is oil and not water. They think that since they look similar at the bulk scale they probably have similar structures. How would you model water (H2O) in order to help explain to them the differences?

• Water molecules have none of the same atoms as oil molecules, so their molecules can’t be modeled the way that oil molecules can.
• Water molecules are much smaller because they only contain one oxygen atom bonded to two hydrogen atoms.
• Water molecules have the same atoms as oil but there are less bonds connecting them together.
• Water molecules are the same size as oil molecules, but water molecules are a repeating pattern of hydrogen and oxygen atoms instead of carbon and hydrogen.

16. Refer to figure A. Your teacher asks you to revise the model for the different fats to clearly show their arrangement when they are in the solid vs liquid state. Which revision would help show this?

• Draw multiple molecules of each fat, with the saturated fat molecules drawn tightly packed together and the unsaturated fat molecules more spaced out.
• Draw the saturated fat molecule with more atoms in it than the unsaturated fat molecule.
• Draw the atoms within each of the molecules more spread out, with the atoms the most spread out in the saturated fats and less spread out in the unsaturated fats.
• Draw the saturated fat molecule with less atoms in it than the unsaturated fat molecule.

17. Refer to figure B. The portion of the molecules written in red are regions of the molecules that have slight charges that can attract other slightly charged molecules, like water. Two students tried modeling this attraction between water and fat. Which student model most clearly shows how two different molecules interact and why?

• Tabby’s model, because they show the bonds that form between different molecules are the same as the bonds that hold atoms within a molecule together by using a solid line.
• Tilly’s model, because they show the different molecules aren’t attracted the same way the atoms within a molecule are by using a dotted line instead of a solid line.
• Tilly’s model, because the water molecules are arranged so the same types of atoms are attracted to each other.
• Tabby’s model, because they show that bonds form between all the atoms of each of the different molecules.

18. Even the oils in peanut butter that are solids are still relatively soft compared to other rigid crystalline structures like sugar. Create a model to show how the arrangement and structure of sugar molecules differs from solid fat/oil molecules.

19. Explain how your model from the last question represents the differences in structure between fat/oils and sugar. What features in your model explain why sugar is more rigid and how does this contribute to sugar’s physical and chemical properties? Justify your response by providing at least two pieces of evidence from the question.

20. Refer to figure B. Which of the models does a better job at showing the water and fat molecules are separate molecules and why?

21. If we zoomed in on the peanut butter, what would we expect to see?

• many different types of molecules
• many of the same type of atom
• there is no way to predict what we would see
• a single molecule of a single type

22. In this example, what are two molecules that are NOT attracted to each other?

• Soap and oil
• Soap and water
• all choices are correct
• Water and oil

23. Is it possible to observe the way these molecules act in your model with our eyes when washing our hands? Why or why not?

24. In the space below, draw a model and label the following parts to show how the these molecules come together when using soap to clean:

1. Soap Molecule
2. Oil molecule
3. Water Molecule

25. Explain how your model shows the way that oil, water, and soap bond together.

26. In the space below, explain why water is a pure substance.