ACAP Review 3

Luna is conducting an experiment where she transfers a gas from one container to another. Which model best represents the behavior of the gas during this transfer?

• model A

• model B

• model C

• model D

Answer explanation

Model B best represents gas behavior as it shows how gas expands to fill its container, demonstrating the principles of gas laws and particle movement when transferred to a new space.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-1

Scarlett is observing a jar of perfume being opened in a room. Which model shows the particles spreading out to fill the entire room?

• model A

• model B

• model C

• model D

Answer explanation

Model B shows the particles evenly distributed throughout the container, indicating they have spread out to fill the entire space. This is in contrast to the other models, which do not depict this behavior.

Maya is conducting an experiment with different objects and liquids. Based on the information, which of the following statements is correct?

• Object B is heavier than Object C.

• Object B is less dense than Liquid 1.

• Object B is less dense than Liquid 3.

• Objects B and C have the same density.

Answer explanation

Object B is less dense than Liquid 1, which indicates it will float in that liquid. The other statements do not provide sufficient evidence to be correct based on the given information.

Tags

NGSS.MS-PS1-2

Elijah is mixing vinegar and baking soda in a sealed plastic bag. The mass of all the contents in the bag before the vinegar touched the baking soda was 20.0 grams. Assuming that the bag is tightly sealed and that nothing escapes from the bag, what mass should Elijah expect to see after the reaction occurs?

• Exactly 20.0 grams because no new matter is created. It is simply rearranged.

• Exactly 20.0 grams because vinegar and baking soda will be the only substances in the bag at the end of the reaction.

• Greater than 20.0 grams because new substances are likely to be formed.

• Greater than 20.0 grams because the bag will probably feel more dense than before the reaction took place.

Answer explanation

The mass remains exactly 20.0 grams because, in a sealed system, matter is neither created nor destroyed. The reaction between vinegar and baking soda rearranges the existing matter, but the total mass stays the same.

Tags

NGSS.MS-PS1-5

Charlotte is creating a model to represent water at 20°C. How should she change the model to best represent the water at this temperature?

• Show the water molecules packed more tightly together.

• Show some of the chemical bonds in the water molecules breaking.

• Show some of the water molecules forming chemical bonds with each other.

• Show the water molecules with longer arrows to represent an increase in motion.

Answer explanation

At 20°C, water molecules have increased kinetic energy, leading to more motion. Showing longer arrows represents this increase in motion, accurately reflecting the behavior of water at this temperature.

Tags

NGSS.MS-PS1-4

Elijah and Grace are conducting an experiment with a clear, colorless liquid. Based on the results, which of the following statements is correct?

• In the clear, colorless liquid, solid A is more soluble than solid B.

• In the clear, colorless liquid, solid B is more soluble than solid A.

• In the clear, colorless liquid, solids A and B are both insoluble.

• Only 4 grams of solid B will dissolve in 8 mL of the liquid.

Answer explanation

The correct statement is that solid B is more soluble than solid A in the clear, colorless liquid, indicating that a greater amount of solid B can dissolve compared to solid A.

Tags

NGSS.MS-PS1-2

Christine is baking cookies and wants to ensure she uses all her ingredients without any leftovers. Which piece of evidence best supports that Christine failed to correctly illustrate conservation of mass?

• Two are two types of ingredients in the dough and two types of ingredients in the baked cookies.

• There are 10 chocolate chips in the dough and 10 chocolate chips in the baked cookies.

• There are 19 sugar crystals in the dough and 14 sugar crystals in the baked cookies.

• The recipe is considered complete because Christine took the ingredients she started with and rearranged them to form new cookies.

Answer explanation

The evidence that there are 19 light gray atoms on the left and 14 light gray atoms on the right indicates a loss of mass, violating the conservation of mass principle. This discrepancy shows Christine's failure to illustrate it correctly.

Tags

NGSS.MS-PS1-5

Based on Christopher’s observations, which claim and piece of evidence best supports whether or not a chemical reaction took place?

• A reaction occurred because there was a phase change.

• A reaction occurred because there was a change in shape.

• A reaction did not occur because there must be a strong odor and phase change if a reaction has taken place.

• A reaction did not occur because no new products were formed. A phase change is a physical change and not a sign of a chemical reaction.

Answer explanation

The correct choice states that a reaction did not occur because no new products were formed. A phase change is a physical change, indicating that the observed change does not confirm a chemical reaction.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Maya stirred two spoonfuls of red clay into a cup of water. Initially, the clay appeared to be evenly mixed throughout the water. The image below shows how the cup appeared several minutes after Maya stopped stirring. Based on the diagram, which term most accurately describes the clay and water?

• compound

• mixture

• solution

• pure substance

Answer explanation

The clay and water form a mixture because they retain their individual properties and can be separated. A compound involves a chemical change, while a solution is a homogeneous mixture, which does not apply here.

Tags

NGSS.MS-PS1-2

Elijah and Abigail are conducting an experiment with different states of matter. Which would best describe a third model that would represent particles of the same substance in a state of matter not represented by model X or model Y?

• The particles would be touching each other and would be located along the sides of the beaker only.

• The particles would be touching each other and would be located in the middle of the beaker only.

• The particles would not be touching each other and would fill the shape of the beaker but not escape it.

• The particles would not be touching each other and would fill the shape of the beaker and escape it.

Answer explanation

The correct choice describes a gas state, where particles are not touching, fill the container's shape, and can escape. This contrasts with solids and liquids, where particles are either touching or confined.