P.5.5. - Overview

Based on the table above, water is a/an ___________ because it is composed of ____________

• atom / one molecule

• atom/more than one molecule

• molecule/atom

• molecule/more than one atom

Tags

NGSS.MS-PS1-1

A student is conducting an investigation to compare physical properties of solids, liquids, and gases. The student observes that solids maintain their shape, liquids flow to take the shape of their container, and gases fill the entire container. Which of the following describes how the spacing of particles relates to these observations?

• Particles that make up solids are packed closely together, so they hold their shape.

• Particles that make up gases are stuck in place, which helps them fill the container.

• Particles that make up liquids are tightly packed, but they cannot move past each other.

• Particles that make up both liquids and solids are spaced the same, but only solids can flow.

A student drops three objects into a container of water: a small rubber ball, a metal coin, and a piece of cork. The student observes that the metal coin sinks, while the rubber ball and cork float. Based on these observations, which of the following best explains why the objects float or sink?

• The coin sinks because it is solid

• The coin sinks because it is heavier than the ball and cork.

•   The ball and cork float because they are denser than water.

• The ball and cork float because they are less dense than water.

A group of students is designing a boat to carry marbles across a small pool of water. They test their first boat, but it sinks when carrying only five marbles. What design improvement could help the boat carry more marbles without sinking?

• building higher walls on the boat

• using a material that absorbs water

• using a material that is more dense

• making the boat’s base wider and flatter

Tags

NGSS.MS-ETS1-1

NGSS.MS-ETS1-2

NGSS.MS-ETS1-3

NGSS.MS-ETS1-4

A student mixes 50 mL of vegetable oil with 50 mL of water in a beaker. After stirring the mixture, the student observes the two liquids separate into layers. Which statement describes the behavior of the substances in this mixture?

• The two substances react chemically to create a new compound.

• The two substances combine into a uniform mixture that cannot be separated.

• The two substances form a solution because they fully combine into one liquid.

• The two substances maintain their original properties because they do not mix.

Tags

NGSS.MS-PS1-2

A student creates two saltwater solutions: Solution A: 1 teaspoon of salt in 1 cup of water

Solution B: 3 teaspoons of salt in 1 cup of water

Which statement correctly compares the two solutions?

• Solution A and Solution B have the same concentration.

• Solution A is more concentrated because it has less salt.

• Solution B is more concentrated because it has more salt.

• Solution B is less concentrated because it has more water.

A group of students is working on separating a mixture of sand, salt, and small iron nails. They need to use the following tools: 1. Magnet 2. Sifter 3. Water 4. Filter 5. Evaporation Dish The students try several combinations of these tools to create an effective system to separate the components. Which method would be most effective for separating sand, salt, and iron nails from the mixture?

• Use the sifter to separate the sand, then use the magnet to remove the nails, and finally dissolve the salt in water.

• Use the magnet to remove the nails, dissolve the mixture in water, filter out the sand, and finally evaporate the water to get the salt.

• Filter all solids from the water, then use the magnet to remove the nails, dissolve the mixture in water, and finally use the sifter to separate the sand.

• Dissolve the salt in water, heat the mixture to evaporate the salt, then use the magnet to remove the nails, and finally use the sifter to separate the sand.

Tags

NGSS.MS-ETS1-2

NGSS.MS-ETS1-3

Which two of the following are evidence that a chemical change has occurred?

• A. A piece of paper is cut into small pieces.

• B. Water freezes into ice cubes in a freezer.

• C. A nail left outside turns rust-colored over time.

• D. A slice of bread turns black after being left in a toaster for too long.

• E. A puddle of water evaporates after being exposed to the heat from the Sun.

Tags

NGSS.MS-PS1-2

A student burns a piece of wood in a campfire. After the fire goes out, only ash and a small amount of unburned wood remain. The student observes that the wood turned into smoke and ash during the fire. What evidence shows that a chemical change occurred when the wood burned?

• The wood melts.

• The wood becomes smaller.

• The ash is turned back into wood.

• The wood changes into ash and smoke.

Tags

NGSS.MS-PS1-2

A student heats a piece of wax until it melts. After the heat is removed, the wax cools and hardens back into a solid. Which of the following sentences explains why this is a physical change?

• The wax changes its mass.

• The wax evaporates when heat is removed.

• The wax returns to its solid state when cooled.

• The wax forms a new substance when it melts.

Tags

NGSS.MS-PS1-4