Chemical Reaction

Which of the following is NOT considered evidence for a chemical reaction?

• Formation of a precipitate.

• Temperature change in the surroundings.

• Change in state (e.g., melting or freezing).

• Emission of light or heat.

Tags

NGSS.MS-PS1-2

In a laboratory experiment, students mix baking soda with vinegar. They notice that the mixture fizzes and produces bubbles. Which of the following statements best explains the observed phenomenon?

• The temperature of the mixture increased, causing it to bubble.

• The baking soda and vinegar underwent a physical change, resulting in the bubbles.

• A chemical reaction occurred, producing a gas that formed bubbles.

• The mixture became denser, causing bubbles to form.

Tags

NGSS.MS-PS1-2

A student mixes together two clear liquids in a beaker and observes that a solid forms at the bottom of the beaker. Which of the following best describes what has happened?

• A physical change has occurred.

• A chemical change has occurred.

• The liquids have evaporated.

• The liquids have dissolved completely.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

When a piece of magnesium ribbon is burned in air, a bright white light is emitted. Which of the following best describes this observation?

• Physical change

• Chemical change

• Change in state

• Change in shape

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Olivia and Mason were having a science experiment in the kitchen. Olivia left a glass of milk on the counter overnight as part of their experiment. The next day, they discovered it had gone sour. This is a (a)   change.

• Physical

• Chemical

Tags

NGSS.MS-PS1-2

Bubbles form when two or more substances are combined is a (a)  

• Chemical Change

• Physical Change

Tags

NGSS.MS-PS1-2

Bubbles form when two or more substances are combined is a (a)   (b)  

• Chemical Change

• Physical Change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

An explosion occurs is a (a)  

• Chemical Change

• Physical Change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

In a chemical reaction between hydrochloric acid and calcium carbonate, carbon dioxide gas is produced. Which piece of evidence best supports the conclusion that a chemical reaction has occurred?

• The mixture turns cloudy.

• The temperature of the mixture decreases.

• Bubbles form in the mixture.

• The mixture changes color.

Tags

NGSS.MS-PS1-2

When iron filings are added to copper sulfate solution, the solution turns blue-green, and a brown solid forms. Which of the following best represents the change observed?

• Physical change

• Chemical change

• Change in state

• Change in shape

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5