States of MatterStates of MatterDensityDensity

BuoyancyBuoyancyViscosityViscosityNOTES!!!NOTES!!!

What is Matter?What is Matter?

Anything that has mass and takes up Anything that has mass and takes up spacespace

So pretty much anything you can So pretty much anything you can imagine – from the air we breathe, to imagine – from the air we breathe, to water we drink, to the sun and all the water we drink, to the sun and all the stars.stars.

4 States of Matter4 States of Matter

SolidSolid LiquidLiquid GasGas PlasmaPlasma

Solid StateSolid State

Lowest energy form of Lowest energy form of mattermatter

Molecules do not change Molecules do not change positionposition

Definite ShapeDefinite Shape Definite VolumeDefinite Volume

Liquid StateLiquid State

Molecules can move Molecules can move around each otheraround each other

Definite volumeDefinite volume Takes shape of containerTakes shape of container

Gas StateGas State

Molecules move freely and Molecules move freely and separate from one anotherseparate from one another

No definite shapeNo definite shape No definite volumeNo definite volume

PlasmaPlasma

Most common state of matter Most common state of matter (in universe)(in universe)

Highest energy form of matterHighest energy form of matter Made up of ionized gas Made up of ionized gas

molecules (atoms breaking molecules (atoms breaking apart due to high heat/energy)apart due to high heat/energy)

DENSITYDENSITY

Two Ways to Measure Two Ways to Measure Matter..Matter..

MassMass VolumeVolume

Density is..Density is..

A property that relates mass A property that relates mass and volume (combines them)and volume (combines them)

Density = mass/volumeDensity = mass/volume OROR Density equals mass per unit Density equals mass per unit

volume (g/cmvolume (g/cm33))

Density affects…Density affects… HardnessHardness (resistance to scratching) (resistance to scratching) ElasticityElasticity (ability to stretch and (ability to stretch and

return)return) BrittlenessBrittleness (likelihood to shatter) (likelihood to shatter) MalleabilityMalleability (ability to made into (ability to made into

thin sheets)thin sheets) Tensile StrengthTensile Strength (how much force (how much force

before breaking)before breaking)

Density of FluidsDensity of Fluids

Tend to be less dense than solidsTend to be less dense than solidsMolecules move around each Molecules move around each otherother

Do not “stack” easilyDo not “stack” easily Water is an exception – ice is less Water is an exception – ice is less

dense than water (due to dense than water (due to structure of water)structure of water)

Density MathDensity Math The density of a material can be The density of a material can be

determined by dividing the mass by determined by dividing the mass by the volumethe volume

Ex. What is the density of a 400 g Ex. What is the density of a 400 g block that has a volume of 16 cmblock that has a volume of 16 cm33??

Answer: 400/16 = 25 g/cmAnswer: 400/16 = 25 g/cm33

ConversionsConversions Sometimes the mass is given in a unit Sometimes the mass is given in a unit

other than grams.other than grams. Or the volume is given in a unit other Or the volume is given in a unit other

than mL.than mL. Ex. What is the density of a block Ex. What is the density of a block

that weighs 2.5 kilograms and has a that weighs 2.5 kilograms and has a volume of 40 cmvolume of 40 cm33??

The mass must be converted into The mass must be converted into grams (g)grams (g)

Answer: 2500/40 = 62.5 g/cmAnswer: 2500/40 = 62.5 g/cm33

Turning things aroundTurning things around

If you are given the density and If you are given the density and volume of a substance, you can volume of a substance, you can determine its mass.determine its mass.

Ex. What is the mass of a block Ex. What is the mass of a block that has a density of 3 g/cmthat has a density of 3 g/cm33 and and a volume of 40 cma volume of 40 cm33??

D=m/v, re-arranged, m=DvD=m/v, re-arranged, m=Dv Answer: 3 X 40 = 120gAnswer: 3 X 40 = 120g

Turning things around.. Turning things around.. Again..Again..

The same can be applied The same can be applied to volume..to volume..

D=m/v, re-arranged, D=m/v, re-arranged, v=m/Dv=m/D

Note…Note…

A cmA cm33 is equivalent to a is equivalent to a mL. Specifically, mL is mL. Specifically, mL is used for volume of gasses used for volume of gasses and liquids and cmand liquids and cm33 is used is used for the volume of solids.for the volume of solids.

BUOYANCYBUOYANCY

DefinitionDefinition

The measure of upward The measure of upward pressure a fluid exerts on pressure a fluid exerts on an objectan object

Buoyancy is…Buoyancy is…

Determined by density Determined by density The denser the fluid, the more The denser the fluid, the more

buoyant force it appliesbuoyant force it applies Ruled by Archimedes’ PrincipleRuled by Archimedes’ Principle

The force exerted on an object by a The force exerted on an object by a liquid is equal to the mass of the liquid is equal to the mass of the fluid displaced by that objectfluid displaced by that object

DisplacedDisplaced

To move something from To move something from its usual placeits usual place

Therefore…Therefore…

If buoyant force is greater If buoyant force is greater than the mass of the object, than the mass of the object, the object FLOATSthe object FLOATS

If buoyant force is less than If buoyant force is less than the mass of the object, the the mass of the object, the object SINKSobject SINKS

Neutral BuoyancyNeutral Buoyancy

Is achieved when the mass of Is achieved when the mass of the object is EQUAL to the the object is EQUAL to the mass of the liquid displaced mass of the liquid displaced by that object.by that object.

The object floats exactly in The object floats exactly in the position it is placed.the position it is placed.

VISCOSITYVISCOSITY

DefinitionDefinition

Measure of a material’s Measure of a material’s resistance to flowresistance to flow

(how hard it is to pour)(how hard it is to pour)

Viscosity is determined by…Viscosity is determined by…

Size of liquid moleculesSize of liquid molecules Shape of liquid moleculesShape of liquid molecules Temperature of liquidTemperature of liquid

Therefore…Therefore…

A thick substance is described A thick substance is described as being very viscousas being very viscousKetchup, syrup (cold)Ketchup, syrup (cold)

Motor oils have different Motor oils have different grades based on viscosity grades based on viscosity (10W-40, 10W-30)(10W-40, 10W-30)