Phases of Matter Solids are a phase of matter that have definite shape and volume Liquids are a phase of matter that can change shape, but not change volume. Gases are the only state of matter that can change shape and volume.

Chemical Properties & Chemical Changes Chemical properties affect chemical changes Chemical properties: flammability (catch fire) Chemical change: silver tarnishing (rust)

Physical Properties of Matter Density: how mass affects volume Solubility: the ability of one material to dissolve in another Volume: amount of space a material occupies Mass: which is the amount of matter in an object

Particle Structure Solids have a tightly compact particle structure Liquids have a fluid particle structure that is farther apart than solids. Gases have the most space between the particles than all of the other phases A temperature increase=bringing the particles farther apart A temperature decrease=decreasing the space

Signs of a Chemical Change Adding of heat Formation of precipitate Formation of gas/oxidation bubbles

Law of Conservation of Mass This law states that mass can never be destroyed because it changes form.

Signs of Physical Change Melting Boiling Evaporating Freezing

Sugar dissolved in Water Example of a physical change Sugar (solid), water (liquid) Sugar is soluble in water Sugar and water have similar physical properties that allow them to physically change when they are mixed together.

Differences between Changes Physical Change Do not break atomic bonds Ex: melting, freezing Electron arrangement is the same and the substance have the SAME identity Chemical Change Do break atomic bonds (“glue”) Ex: rust, burned Electrons are rearranged to create a NEW substance