🔵 PHYSICAL CHANGES
What type of change alters the size, shape, form, or state of a substance without making a new substance?
What is a physical change?
What type of change produces one or more new substances?
What is a chemical change?
Bubbles unexpectedly form when two substances are mixed. What might the bubbles indicate?
A gas has formed, which can be evidence of a chemical change.
Melting ice
Physical
What are the two main types of changes discussed in the video?
Physical and chemical changes.
Ice melting into liquid water is what type of change?
What is a physical change?
Burning wood is what type of change?
What is a chemical change?
A substance unexpectedly changes color. What might this indicate?
A chemical change may have occurred.
Burning wood
Chemical
What familiar substance does the video use to demonstrate physical changes involving states of matter?
Water.
When liquid water freezes into ice, has a new substance been created?
No. It is still water.
Why is digesting food considered a chemical change?
The food is chemically changed into new substances.
A reaction unexpectedly becomes warmer. What kind of evidence is this?
A temperature/energy change.
Water boiling
Physical
What food example is used to demonstrate changes that happen during cooking?
Baking cookies.
Name two changes of state that are physical changes.
Examples: melting, freezing, boiling/evaporation, or condensation.
What happens to particles during a chemical change?
They rearrange to form new substances.
Name two observations that can provide evidence of a chemical change.
Examples include gas production, unexpected color change, temperature change, light, odor change, or formation of a new solid.
Digesting food
Chemical
What happens to the identity of a substance during a physical change?
Its identity stays the same.
Why is changing the state of water considered a physical change?
Water changes form or state, but its identity remains the same.
What is the biggest difference between a physical and chemical change?
A chemical change creates a new substance; a physical change does not
Why should scientists look for several pieces of evidence before deciding that a chemical reaction occurred?
Some physical changes can look similar, so scientists need evidence that a new substance formed.
Baking cookie dough into cookies
Chemical — new substances form during baking. The video also uses baking as an example for discussing physical and chemical changes.
A student says, “If something changes how it looks, it must be a chemical change.” Explain why the student is incorrect.
Changing appearance alone does not prove that a new substance formed. A physical change can change size, shape, form, or state without changing the substance's identity.