Chemical Reactions vs Physical Changes

The substances that go into a chemical reaction are called

• reactants

• products

• molecules

• mixtures

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NGSS.MS-PS1-5

What is a chemical change?

• When you mix two substances

• The change of physical properties

• When molecules react with each other and form a new molecules

• When a solid turns into a liquid

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is a clue that a chemical change has occurred? (Choose all correct answers.)

• Formation of a gas (bubbles)

• Color change

• Phase change

• Produces light or heat

Tags

NGSS.MS-PS1-2

This image shows what happens when methane gas (CH₄) is burned (reacts with oxygen O₂). This represents a chemical change because

• there is only one carbon atom.

• the products and reactants are made of atoms and molecules.

• there are the same number of atoms before and after.

• the atoms have rearranged to form new molecules.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is a sign that a chemical reaction has occurred?

• change in shape

• melting

• formation of a gas

• dissolving

Tags

NGSS.MS-PS1-2

Is melting butter for popcorn a chemical or physical change?

• chemical

• physical

A change where one or more new substances are created.

• Physical Change 

• Chemical Change 

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

Fizzing, foaming, and burning are all examples of

• Chemical change

• Physical change

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NGSS.MS-PS1-2

Rust on an iron bar is an example of chemical change.

• True

• False

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

When you break a cracker into pieces it is a...

• Chemical change

• Physical change