Question

which of these is an example of a physical change?

• a banana ripening in the air
• hydrogen burning in the air
• zinc reacting with an acid
• liquid water turning into vapor

Explanation:

A physical change alters form without changing substance. Water turning to vapor is a phase - change (liquid to gas) without new substances formed. Zinc reacting with acid, hydrogen burning, and banana ripening are chemical changes forming new substances.

Answer:

Liquid water turning into vapor