Notes on Three States of Matter M. Pursley 8th Science

Three states of matter Solid Liquid Gas

Particle Movement Solid – particles are packed close together Particles move by vibrating in place (but they cannot break the attraction to one another) Particles are locked in place Have definite shape and volume

Particle Movement Liquid – particles overcome some attraction and slide past each other Liquids take the shape of their container Has a definite volume (volume stays the same no matter what container the liquid is in or what shape the container is) Liquids for spherical drops

Particle Movement (liquid) VISCOSITY – Resistance to flow – ? – which is more viscous – syrup or water Answer Viscosity = Resistance to flow so syrup would be more resistant to flow

Particle Movement (Gas) Gases – particles move very quickly Gas particles move independently of each other Little attraction between particles No definite shape or volume

Temperature and Particle Movement TEMPERATURE – a measure of how fast particles move effects particle movement Hot – particles move fast and spread out (which could cause a balloon to blow up) Cold – particles move slow and get close together (can cause a balloon to shrink)

Boyle’s Law Boyle’s Law As pressure decreases the volume of the gas increases Ex. Pushing down on a piston (pump) increases the pressure and decreases the amount of gas that can be held within the pump (therefore it will come out) As pressure increases the volume of gas decreases If I raise up the handle on the pump – it allows for more room for the gas molecules to move

Boyles Law continued If the handle is raised up – it allows more room for the gas particles to move If the handle is pushed down – it allows less room for the gas particles to move

Charles’s Law Charles’ Law Temperature affects volume of the gas If temperature is high – particles move fast – and the volume expands (get bigger) If temperature is cold – particles slow down and stick together – volume shrinks

Changes of state – Physical Properties Change of State - Occurs due to heating or cooling of a substance (adding or removing energy)

5 Changes of State Melting – solid to liquid Melting point – temp at which a solid becomes a liquid Freezing – liquid to solid Freezing pt – temperature at which a liquid becomes a solid Evaporation – liquid to gas Boiling point – temp at which a liquid becomes a vapor/gas Condensation – gas to liquid Condensation pt – temp at which a gas becomes a liquid sublimation – solid to gas

Pictures of Changes in State

Endothermic vs. Exothermic Endothermic change – (particles) gains energy when it changes state (solid to liquid) Exothermic – (particles )loses energy when it changes state (liquid to solid) Examples – Endothermic – an ice cube melts Example of exothermic – water freezes