Which question best distinguishes a chemical change from a physical change?

Paolo crushes a sugar cube. How does the chemical composition of the pieces compare with that of the cube?

Liza crumples a paper sheet into a ball. How should she classify what happened?

A glass tumbler shatters and cannot easily be repaired. Which description correctly identifies both the change and its reversibility?

A teacher heats sugar until it browns and develops a new smell. Which kind of change do these observations suggest?

Which everyday event matches the change shown in the particle diagram?

Compare the particles before and after the arrow. What kind of change is shown?

What makes up the visible white cloud near the spout of a boiling kettle?

Why can freezing restore solid ice from its meltwater?

Ana stirs black pepper into vinegar. Which category describes preparing this classroom mixture?

Which event changes an object's form without making a different substance?

Which observation is evidence of gas production when baking soda is added to vinegar?

Rico sees pockets of vapor rise through heated water. Does this observation alone prove that a different substance formed?

A learner already wears ordinary prescription eyeglasses. What should they do before the vinegar-and-baking-soda activity?

An iron nail develops a reddish-brown coating after weeks outdoors. Which description applies?

An aging leaf loses its green color. What happens to the green pigment as the leaf ages?

Why does cooling a baked cake not restore the original flour and eggs?

Which part of digestion is a chemical change?

Which pair includes one physical change and one chemical change?

Cup A contains pepper stirred into vinegar. Cup B contains a little baking soda mixed with plenty of vinegar. Which added solid can be recovered unchanged by filtering?