6th grade CRT Review/Diagnostic

A student is conducting an experiment to understand how light behaves when it hits different materials. She uses a mirror, a piece of black cloth, and a glass window. Which of the following models best describes the behavior of light in this experiment?

• Light is only absorbed by all materials.

• Light is reflected by the mirror, absorbed by the black cloth, and transmitted through the glass window.

• Light is only transmitted through all materials.

• Light is only reflected by all materials.

Answer explanation

In this experiment, the mirror reflects light, the black cloth absorbs it, and the glass window transmits light. Thus, the correct model is that light is reflected by the mirror, absorbed by the black cloth, and transmitted through the glass.

Tags

NGSS.MS-PS4-2

Imagine you are designing a pair of sunglasses. You want to reduce glare from the sun while allowing some light to pass through. Which combination of materials would you choose to achieve this, based on your understanding of wave behavior?

• A) A material that only reflects light.

• B) A material that absorbs all light.

• C) A material that both absorbs and transmits light.

• D) A material that only transmits light.

Answer explanation

Choice C is correct because a material that both absorbs and transmits light can reduce glare by absorbing some light while still allowing enough light to pass through for visibility.

Tags

NGSS.MS-PS4-2

A scientist is studying how sound waves interact with different surfaces. She notices that sound behaves differently when it hits a wall compared to when it hits a curtain. What reasoning can she use to explain this observation?

• Sound waves are only reflected by both the wall and the curtain.

• Sound waves are absorbed by the wall and transmitted through the curtain.

• Sound waves are reflected by the wall and absorbed by the curtain.

• Sound waves are transmitted through both the wall and the curtain.

Answer explanation

The wall reflects sound waves due to its hard surface, while the curtain absorbs them because of its soft, porous material. This difference in interaction explains why sound behaves differently when hitting these surfaces.

Tags

NGSS.MS-PS4-2

How do sensory receptors in the human body contribute to the formation of memories?

• A) They directly store memories in the brain.

• B) They send messages to the brain, which can be stored as memories.

• C) They create memories independently of the brain.

• D) They only respond to stimuli without affecting memory.

Answer explanation

Sensory receptors detect stimuli and send signals to the brain. This information can then be processed and stored as memories, making option B the correct choice.

Tags

NGSS.MS-LS1-8

Consider a scenario where you touch a hot surface. Describe the process that occurs from the moment you touch the surface to the reaction of pulling your hand away.

• The skin burns, and the brain sends a message to the hand to move.

• Sensory receptors in the skin detect the heat and send a message to the brain, which then sends a signal to the muscles to pull the hand away.

• The brain immediately knows the surface is hot and moves the hand.

• The muscles in the hand automatically react without any brain involvement.

Answer explanation

When you touch a hot surface, sensory receptors in the skin detect the heat and send a message to the brain. The brain then processes this information and sends a signal to the muscles to pull the hand away, ensuring a quick reaction.

Tags

NGSS.MS-LS1-8

Explain how sensory receptors and the brain work together to help you remember the smell of your favorite food.

• Sensory receptors in the nose store the smell as a memory.

• The brain creates the smell without any input from sensory receptors.

• Sensory receptors in the nose detect the smell and send signals to the brain, where the information is processed and stored as a memory.

• The brain detects the smell and stores it as a memory without sensory input.

Answer explanation

Sensory receptors in the nose detect the smell of food and send signals to the brain. The brain processes this information and stores it as a memory, allowing you to remember the smell of your favorite food.

Tags

NGSS.MS-LS1-8

A student is observing a block of ice melting into water. Which model best describes the change in particle motion and state of the substance as thermal energy is added?

• Particles move slower and the substance changes from solid to gas.

• Particles move faster and the substance changes from solid to liquid.

• Particles move slower and the substance changes from liquid to solid.

• Particles move faster and the substance changes from liquid to gas.

Answer explanation

As thermal energy is added, the particles in the ice move faster, leading to a change in state from solid to liquid. This is the process of melting, where the solid ice transitions to liquid water.

Tags

NGSS.MS-PS1-4

Consider a sealed container with water at room temperature. If thermal energy is removed from the water, which of the following predictions about the water’s state and particle motion is most accurate?

• A) The particles will move faster, and the water will become a gas.

• B) The particles will move slower, and the water will become a solid.

• C) The particles will move faster, and the water will remain a liquid.

• D) The particles will move slower, and the water will remain a liquid.

Answer explanation

Removing thermal energy causes water particles to lose kinetic energy, resulting in slower movement. As the temperature decreases, water can freeze and become a solid, making option B the most accurate prediction.

Tags

NGSS.MS-PS1-4

A scientist is heating a sample of a pure substance. She notices that the temperature remains constant for a period of time even though thermal energy is continuously added. What is the most likely explanation for this observation?

• The substance is undergoing a chemical reaction.

• The substance is changing state from liquid to gas.

• The substance is losing energy to the surroundings.

• The substance is changing state from gas to liquid.

Answer explanation

The constant temperature indicates a phase change. When a substance changes state from liquid to gas, it absorbs thermal energy without increasing temperature, which explains the observation.

Tags

NGSS.MS-PS1-4

A group of students is designing a device to keep a cup of hot water warm for as long as possible. Which material should they choose for the outer layer of their device to minimize thermal energy transfer?

• Aluminum

• Copper

Answer explanation

Aluminum is a better choice than copper for minimizing thermal energy transfer due to its lower thermal conductivity. This property helps keep the hot water warm for a longer period by reducing heat loss.

Tags

NGSS.MS-PS3-3