Use the information in this box to answer questions 1 - 4:
Kevin buys a new bottle of gatorade from the store. He takes it home and weighs it. The bottle weighs 450 grams. Then Kevin puts the water bottle in the freezer until it solidifies. He takes it out and weighs it again.
2 points
2
Question 1
1.
How did the molecules in the gatorade change as they solidified? (2 pts)
A) The molecules started moving faster and got farther apart
B) The molecules started moving slower and got closer together
D) The molecules got bigger and stopped moving.
2 points
2
Question 2
2.
Kevin buys a new bottle of gatorade from the store. He takes it home and weighs it. The bottle weighs 450 grams. Then Kevin puts the water bottle in the freezer until it solidifies. He takes it out and weighs it again.
How much would you expect the gatorade bottle to weigh after it solidified? (2 pts)
A) Less than 450 grams
B) Exactly 450 grams
C) More than 450 grams
2 points
2
Question 3
3.
Which statement best describes how the Gatorade is different after it solidified? (2 pts)
A) It is a liquid.
B) It weighs more.
C) It stays in one shape.
2 points
2
Question 4
4.
Gatorade is a mixture of water, sugar, and food coloring. Which of these models could be a model of the particles in gatorade? (2 pts)
2 points
2
Question 5
5.
Which of the following objects are on a nanoscale, and cannot be viewed with the human eye? Select ALL that apply. (2 pts)
A) A grain of salt
B) An atom
D) A molecule of water
2 points
2
Question 6
6.
Which of the following statements are true? Select ALL that apply. (2 pts)
A) When a solid “disappears” (can't see) into a liquid, it has actually dissolved.
B) All solids will dissolve when mixed with a liquid.
D) Stirring a mixture of a solid and a liquid helps the solid dissolve.
Use the information in this box to answer questions 7 - 12:
Keisha and her younger sister are helping their mom to make dinner. Keisha’s mom asks her to get the flour so that she can make gravy. When Keisha looks in the cabinet, she sees two clear containers with white powders. Her mom says one is baking soda and one is flour, but they aren’t labeled. She needs to figure out which one is flour.
Keisha remembers an experiment she did in her science class about identifying different powders. She gets her science notebook, and turns to her data:
2 points
2
Question 7
7.
Keisha decides to mix both of the unlabeled powders into water and observe what happens. She puts 10 grams of each powder into two different cups. Each cup contains 100 grams of water. She stirs each mixture for 60 seconds.
How much would you expect each mixture of water and powder to weigh? (2 pts)
A) 90 grams
B) 100 grams
C) 110 grams
Use this data table as evidence to answer Question 8 and 9
4 points
4
Question 8
8.
Why did Keisha choose to use the property of solubility in water, and not the particle size or color to identify the two powders? (4 pts)
Sentence starters:
Claim: Keisha used the solubility because _________________
Evidence: In the data table of powder properties, it shows _________________
Reasoning (Explanation): Explain your claim (answer) for why Keisha used the property of solubility.
When Keisha mixed each powder with water, she got the following results:
2 points
2
Question 9
9.
Identify each powder, based on the experiment’s results. Choose TWO answers, one answer for Powder A and one answer for Powder B. (2 pts)
A) Powder A is baking soda.
B) Powder A is flour.
C) Powder B is baking soda.
D) Powder B is flour.
2 points
2
Question 10
10.
After Keisha mixed Powder A with water, her little sister said, “Wow! The powder just disappeared! It’s totally gone!” Which statement would best explain what really happened to the powder? (2 pts)
A) Powder A reacts with water to make a brand new substance.
B) Powder A broke down into smaller and smaller particles until it did disappear completely from the water.
C) Powder A breaks down into smaller particles that are mixed evenly throughout the water.
2 points
2
Question 11
11.
Why is the baking soda soluble in water and the flour is not? (2 pts)
A) The baking soda particles are smaller than the flour particles, so they fit between the water better.
B) The baking soda molecules are attracted to the water molecules, and the flour molecules are not.
C) Keisha probably mixed the baking soda for a longer time than she mixed the flour.
Keisha’s sister is still having difficulty understanding what is happening, so she draws two models to explain what happened at the nanoscale level.
Use these models as evidence to answer Question 12
4 points
4
Question 12
12.
Which of these models shows the baking soda and water mixture? How do you know? (4 pts)
Sentence starters:
Claim: Model ____ shows baking soda and water.
Evidence: In Model ____, it shows _________________
Reasoning (Explanation): This means Model ____ is baking soda and water because _________________
Use the information in this box to answer questions 13-14:
After figuring out which powder is flour, Keisha’s mom makes gravy. Keisha notices that two of the ingredients her mom uses are water and chicken fat. When the water and chicken fat are mixed together, the mixture separates into layers. When Keisha’s mom adds gelatin to the mixture and stirs, the gravy stays mixed.
Keisha draws a diagram of the mixture before and after adding the gelatin in her notebook.
4 points
4
Question 13
13.
Which of the following statements about the water, fat and gelatin molecules are true? Select ALL that apply. (4 pts)
A) Water molecules are attracted to other water molecules
B) Fat molecules are attracted to other fat molecules
C) Water molecules are attracted to fat molecules
D) Water molecules are attracted to gelatin molecules
E) Fat molecules are attracted to gelatin molecules
Use the model below to answer Question 14
2 points
2
Question 14
14.
Keisha’s sister drew a model of the water, fat and gelatin molecules in the gravy. Is her model accurate? If not, why not? (2 pts)
A) It is accurate because it shows the water and fat molecules attracted to the gelatin molecule.
B) It is not accurate because it shows water and fat molecules attracted to each other.
C) It is not accurate because it shows gelatin molecules attracted to each other.
After figuring out which powder is flour, Keisha’s mom makes gravy. Keisha notices that two of the ingredients her mom uses are water and chicken fat. When the water and chicken fat are mixed together, the mixture separates into layers. When Keisha’s mom adds gelatin to the mixture and stirs, the gravy stays mixed.
Keisha draws a diagram of the mixture before and after adding the gelatin in her notebook.
Model:
7 points
7
Question 15
15.
Based on your investigations into emulsifiers during this unit, why do water and fat separate into layers when they are stirred together, but completely mix when gelatin is stirred in? (7 pts)
Sentence starters:
Claim: Water and fat separate into layers because ___________ . Water and fat completely mix when gelatin is added and stirred because ___________.
Evidence: In the model, it shows _______________
Reasoning: When liquids separate, this means _________________. These liquids mix when _________________ because _________________
