The States of MatterThe States of Matter

AC Physical ScienceAC Physical Science

Fall 2009Fall 2009

Solids…Solids…

Has a definite volume and definite Has a definite volume and definite shapeshape

Particles are packed very tightly Particles are packed very tightly togethertogether

Particles stay in a fixed positionParticles stay in a fixed position

Types of solids…Types of solids…

Crystalline - made of crystals…Crystalline - made of crystals…examples: salt, sugar, sand, snow – examples: salt, sugar, sand, snow – melts at the melting pointmelts at the melting point

Amorphous solid – solids not Amorphous solid – solids not arranged in a regular pattern…arranged in a regular pattern…examples: plastics, rubber, and glass examples: plastics, rubber, and glass – does not have a distinct melting – does not have a distinct melting point. Instead the material becomes point. Instead the material becomes softer as it is heated.softer as it is heated.

Liquids…Liquids…

Has no shape of its ownHas no shape of its own Takes the shape of the containerTakes the shape of the container Do not expand or compress easilyDo not expand or compress easily Particles packed closelyParticles packed closely Particles move around freelyParticles move around freely Viscosity – resistance of a liquid to Viscosity – resistance of a liquid to

flowing or how easily a liquid flows…high flowing or how easily a liquid flows…high viscosity flows slowly (molasses) and low viscosity flows slowly (molasses) and low viscosity flows fast (water, rubbing viscosity flows fast (water, rubbing alcohol, engine oil).alcohol, engine oil).

Gases…Gases…

Changes volume very easilyChanges volume very easily Volume and shape is the same as the Volume and shape is the same as the

containercontainer Does not have definite shape or Does not have definite shape or

volumevolume Feel your chest expand and contract Feel your chest expand and contract

when you breathe.when you breathe.

Pressure…Pressure…

Force of the outward push on a container Force of the outward push on a container exerted by a gasexerted by a gas

Pressure = Force / AreaPressure = Force / Area Pressure is related to volumePressure is related to volume Boyle’s LawBoyle’s Law – relationship between – relationship between

pressure and volume of a gas…when pressure and volume of a gas…when pressure is increased at a constant pressure is increased at a constant temperature – the volume of the gas temperature – the volume of the gas decreases…when the pressure decreases, decreases…when the pressure decreases, volume increasesvolume increases

Temperature…Temperature…

Charles’ LawCharles’ Law – when temperature of – when temperature of a gas increases at a constant a gas increases at a constant pressure, the volume increases…pressure, the volume increases…when temperature decreases, when temperature decreases, volume decreasesvolume decreases

Plasma???Plasma??? Defined as an “Ionized Gas” – in other words Defined as an “Ionized Gas” – in other words

dealing with the sharing of electrons…dealing with the sharing of electrons… Plasma is considered a conductor and is Plasma is considered a conductor and is

strongly attracted to electromagnetic fields.strongly attracted to electromagnetic fields. Examples: lightening, the ionosphere, and the Examples: lightening, the ionosphere, and the

aurora borealis – all occurring in nature. In aurora borealis – all occurring in nature. In space – the sun and stars (created by fusion), space – the sun and stars (created by fusion), solar winds and space itself is said to be solar winds and space itself is said to be plasma. Man-made plasma…TV’s, neon signs, plasma. Man-made plasma…TV’s, neon signs, fluorescent lamps, etc. fluorescent lamps, etc.

Chemical Properties Chemical Properties and Changes…and Changes…

Chemical Properties – the chemical makeup Chemical Properties – the chemical makeup of a substanceof a substance

Chemical Changes – occurs when Chemical Changes – occurs when compounds are created or destroyed…compounds are created or destroyed…breaks in chemical bonds occur - should breaks in chemical bonds occur - should included color change, bubbles, or a included color change, bubbles, or a precipitate (a crystalline solid) forming…precipitate (a crystalline solid) forming…examples: burning wood, mixing an acid examples: burning wood, mixing an acid with a base, melting a piece of plastic…a with a base, melting a piece of plastic…a simple state change does NOT always mean simple state change does NOT always mean a chemical change has occurred.a chemical change has occurred.

Physical Properties and Physical Properties and Changes…Changes…

Sublimation – solid changes to gas – Sublimation – solid changes to gas – happened at really cold temperatures…happened at really cold temperatures…the solid does not go through the liquid the solid does not go through the liquid state (dry ice).state (dry ice).

Physical Properties – observable Physical Properties – observable properties of a substance (color, size, properties of a substance (color, size, etc.)etc.)

Physical Changes – change that occurs Physical Changes – change that occurs without changing the identity of the without changing the identity of the substance (wood being chopped…carrots substance (wood being chopped…carrots being sliced)…being sliced)…