Question

period: 3rd
skill 5 teacher score: 0 1 2 3 4
assessment #01 - density
the dead sea is known as a popular tourist attraction on the border of jerusalem and jordan, in the middle east. tourists frequently take crazy photos of themselves relaxing in the body of water. a science student provides the following explanation about the popular photos when asked, how can this person float so high out of the water?
students argument: the dead sea is a place where you can float really high in the water because its super salty. the salt makes the water denser than your body, so you naturally float on top, just like how a balloon floats in the air. you can just chill and enjoy the unique feeling of floating without much effort.
part a: highlight the students claim, and underline any factual evidence used.
part b: in the space below, explain how this students evidence supports their claim.
part c: using the data collected from the density block activity in class, create a scientific argument to answer the guiding question: what will happen to the soda cans if salt was gradually added to the water?
hot tip: use your brace map to ensure you have all the parts of an argument in your writing
part d: assessing your own performance (circle one)
skill 5. scientific explanations (cer+)
emerging (1)
i can identify and evaluate how claims, evidence, and reasoning are used in a scientific argument.
developing (2)
i can explain the connection between a scientific claim and the evidence used to support it.
approaching (3)
i can create an argument which contains multiple types of evidence that supports a claim.
proficient (4)
i can create an argument that includes complex reasoning that explains how the evidence supports a claim.

Explanation:

Part A:

The claim is "The Dead Sea is a place where you can float really high in the water because it's super salty. The salt makes the water denser than your body, so you naturally float on top, just like how a balloon floats in the air. You can just chill and enjoy the unique feeling of floating without much effort." The factual evidence is that the Dead Sea is super - salty and salt makes water denser than the human body.

Part B:

The evidence supports the claim as density is a key factor in buoyancy. When the water is denser than the body (due to high salt content in the Dead Sea), the buoyant force is greater, allowing people to float higher, similar to how a less - dense balloon floats in denser air.

Part C:

As salt is gradually added to water, the density of the water increases. If the density of the water becomes greater than the density of the soda cans (which is a combination of the can material and the liquid inside), the soda cans will float higher in the water. A scientific argument would include a claim (soda cans will float higher), evidence (data from density block activity showing density - buoyancy relationship and the fact that adding salt increases water density), and reasoning (explaining how increased water density affects the buoyant force on the soda cans).

Part D:

This part is self - assessment. For example, if a student can identify and evaluate claims, evidence, and reasoning in a scientific argument, they might circle "Emerging (1)". If they can explain the connection between a scientific claim and evidence, they might circle "Developing (2)". If they can create an argument with multiple types of evidence, they might circle "Approaching (3)". If they can create a complex reasoning to explain how evidence supports a claim, they might circle "Proficient (4)".

Answer:

Part A:

Claim: "The Dead Sea is a place where you can float really high in the water because it's super salty. The salt makes the water denser than your body, so you naturally float on top, just like how a balloon floats in the air. You can just chill and enjoy the unique feeling of floating without much effort."
Evidence: The Dead Sea is super - salty; salt makes water denser than the human body.

Part B:

Density affects buoyancy. Higher water density due to salt means greater buoyant force, allowing people to float higher.

Part C:

Claim: Soda cans will float higher as salt is added to water. Evidence: Data from density block activity; adding salt increases water density. Reasoning: Increased water density increases buoyant force on soda cans.

Part D:

Self - assessment based on individual ability levels as described above.