Review Chemical Reaction & Physical Changes

Fire is an example of a chemical change, what is produced in a chemical change?

• The same substances, but with different properties

• Completely different new substances

• Substances that can be easily reversed

• A simple mixture of the original substances

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is a chemical reaction?

• A simple mixture of substances

• The process of converting substance into energy

• The process of converting substances into different substances

• The natural decomposition process of substances

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is the common characteristic of all chemical reactions?

• Produce new substances, identical to the original substances

• The reaction is reversible, and the original substances can be easily recovered

• Produce new substances, different from the original substances

• The reaction is irreversible, and the original substances cannot be easily recovered

Tags

NGSS.MS-PS1-5

At the end of a chemical reaction, which of the following is correct?

• Can easily get back the original substances

• The reaction is reversible

• What is produced is a simple mixture of the original substances

• Cannot easily get back the original substances

Tags

NGSS.MS-PS1-2

How do you know a chemical reaction has occurred in the laboratory?

• Smelling sweetness or foul odor.

• Feeling the chemical substances getting hot or cold on their own.

• Hearing a loud explosion or a slight hissing sound, indicating gas has been produced.

• Formation of a precipitate, the product looks like a cloudy solid.

Tags

NGSS.MS-PS1-2

Which is a sign of a chemical reaction?

• Smelling a sweet or foul odor.

• Feeling a chemical substance spontaneously heat up or cool down.

• Hearing a loud explosion or a faint hissing sound, indicating gas has been produced.

• Formation of a precipitate, the product looks like a cloudy solid.

Tags

NGSS.MS-PS1-2

Which sign of a chemical reaction indicates that gas has been produced?

• Smelling sweetness or foul odor.

• Feeling the chemical substance spontaneously heat up or cool down.

• Hearing a loud explosion or a slight hissing sound, indicating that gas has been produced.

• Formation of a precipitate, the product looks like a cloudy solid.

What does the precipitate formed in a chemical reaction look like?

• Smells sweet or foul.

• Feels the chemical substance heating up or cooling down on its own.

• Hears a loud explosion or a slight hissing sound, indicating gas has been produced.

• Forms a precipitate, the product looks like a cloudy solid.

In the reaction between baking soda and vinegar, which of the following is not a sign of a chemical change?

• Formation of gas

• Change in temperature

• Loud reaction sound

• Change in shape

Tags

NGSS.MS-PS1-2

In physical changes, which of the following is correct?

• Formation of a new substance

• No new substance is formed

• Formation of gas

• Significant temperature change