Question

physical and chemical changes
note-taking guide
directions: complete the note-taking guide using the word bank below. to enter your answers, click on the blanks and type.
word bank: absorbs, -science, -engineer, color, invisible, carbon dioxide, copper oxide, precipitate, physical change, chemical change, law of conservation of mass, heat, chemical, breaks, stronger, evaporation, gas
a single piece of paper can be folded or cut into many shapes. how is the paper changed?
only the shape of the paper has __. the paper is still paper. no new substances are formed, and the amount of mass is the same. this is a __.
this is most often seen when water freezes or ice melts. only the state of matter changes. water is still water. no new ____ formed, and the amount of matter is the same.
if we now mix salt with water, how would you explain the change?
a mixture of salt and water is called a __. when you mix salt in water to make a solution, you cannot see the salt because it’s evenly with the __ of water, but it is still there. making a solution is a physical change because no new substances are formed.
if we burn paper to start a campfire, how is paper changed now?
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Explanation:

The problem is about physical and chemical changes, which falls under Chemistry (a subfield of Natural Science). For the first fill - in (how a single piece of paper folded or cut changes): When a paper is folded or cut, only its shape (or size) changes. No new substance is formed. So the change is physical. For the second fill - in (what kind of change is folding/cutting paper): Since no new substance is created and just the physical appearance (shape) is altered, it's a physical change. For the third fill - in (what happens to the shape of the paper): The shape of the paper is changed (like folded or cut into pieces). For the fourth fill - in (type of change when water freezes or boils): When water freezes to ice or boils to steam, it's a physical change because the chemical composition (H₂O) remains the same, only the state (solid/liquid/gas) changes.

Answer:

1. For the first blank (how the paper changes when folded/cut): The shape (or size) of the paper changes. No new substance is formed.
2. For the second blank (type of change for folding/cutting paper): physical change
3. For the third blank (what happens to the paper's shape): changed
4. For the fourth blank (type of change for water freezing/boiling): physical change