Science 2 Reviewer

Matter

Anything that has weight and takes up space.

States of Matter

Different forms in which matter can exist: solid, liquid, gas.

Solid

Has a definite shape and size.

Liquid

Takes the shape of its container.

Gas

No definite shape or size; spreads out.

Malleable

Can be hammered or pressed into a new shape.

Elastic

Can stretch and return to original shape.

Viscous

A thick liquid that flows slowly.

Brittle

Breaks or shatters easily.

Flexible

Bends easily without breaking.

Physical Change

Size/shape/state/appearance changes; no new substance formed.

Chemical Change

A new substance is formed; hard to reverse.

Change in Size

Examples include cutting paper, chopping vegetables, and tearing fabric.

Change in Shape

Examples include molding clay, folding paper, and crumpling foil.

Change in State

Examples include melting ice and evaporating water.

Change in Color (Physical)

Mixing or appearance change without a new substance.

Change in Texture

Examples include sanding wood and grinding rice to flour.

Change in Color (Chemical)

Indicates a chemical change, e.g., iron rusting.

Change in Smell

Examples include milk turning sour and rotting garbage.

Which of these is NOT a physical change: Cutting paper, Burning wood, Melting ice?

Burning wood is a chemical change because a new substance (ash, smoke, gases) is formed, and it's hard to reverse. Cutting paper and melting ice are physical changes.

Identify the physical change from the following: Iron rusting, Baking a cake, Tearing fabric.

Tearing fabric is a physical change as only its size and shape change, but no new substance is formed. Rusting iron and baking a cake are chemical changes.

Which statement about gases is incorrect? Gases have a definite shape. Gases spread out to fill their container. Gases have no definite size.

The statement 'Gases have a definite shape' is incorrect. Gases have no definite shape or size; they take the shape and volume of their container.