Physical Changes and Chemical Reactions

Students conducted an investigation and their observations are shown below. Which observations show that a chemical reaction occurred?

• Observations 1 & 4
• Observations 1 & 2
• Observations 2 & 3
• Observations 3 & 4

Tags

NGSS.MS-PS1-2

The image below shows a chemical reaction taking place. What evidence proves there was a chemical reaction?

• Light produced
• Formation of gas
• Color change
• Precipitate formed

Tags

NGSS.MS-PS1-2

In a process of baking cupcakes, a chemical reaction takes place. What evidence best justifies that a chemical change took place?

• A Change in shape
• Cake rises as bubbles form
• The water evaporates
• A Change in size

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Iron rusting is an example of a chemical change. What evidence shows that a chemical reaction has taken place?

• Unexpected temperature change
• A solid substance is formed
• Production of light and heat
• Unexpected color change and a new substance (RUST) formed

Tags

NGSS.MS-PS1-2

In the process of burning a piece of wood, a chemical reaction takes place. What evidence best justifies that a chemical change took place?

• A new substance is produced.
• The size of the wood changes.
• The shape of the wood changes
• The wood is made up of more than one element.

Tags

NGSS.MS-PS1-2

A student placed a shiny, silver-colored strip of zinc metal in the solution and observed the changes. What evidence supports the observation that a chemical reaction occurred?

• The metal strip below the surface of the solution is not shiny and has a lighter coat material
• The metal strip below the solution is lighter in color
• The metal strips below the surface has a dark coat material.
• The metal strips is shiny below the surface of the solution.

Tags

NGSS.MS-PS1-2

The diagram shows an experiment with two test tubes. Which observation is NOT consistent with the results shown?

• The liquid in both test tubes remains clear

• Both test tubes contain the same initial substances

• A color change is observed in both test tubes

• Equal amounts of iodine solution were added to each test tube

Tags

NGSS.MS-PS1-2

A student mixes two solutions. After a few minutes, a white powder can be seen setting at the bottom of the test tube. From these observations, the student can conclude that the two clear liquids

• have undergone a change in state
• have been mixed too long and are no longer good
• have combined to form a new substance
• have been combined and the substance stays the same

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

For a lab investigation, a student observes several changes in a test tube. Which of the following would indicate that a physical change has taken place?

• Substance 1
• Substance 3
• Substance 2
• Substance 4

A student observes some sugar as it is heated and burns. The student concluded that a chemical reaction has occurred. Which of the following observations about the burning sugar provides evidence of a chemical reaction?

• Substance 1
• Substance 3
• Substance 2
• Substance 4

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5