IPC Unit 2: Properties of Matter

Matter is anything that has mass and volume.1. Mass is a measure of the amount of matter.2. Volume is the amount of space an object occupies.

• Demo: Will an inflated balloon weigh more, less, or the same as the same balloon deflated? Obtain mass of balloon, inflate and obtain mass.

For Example:

• Your book, your desk, your lunch, the air that you breathe and the water you drink are all made of matter.

Classifying Matter

Pure Substances Pure Substances - only one type of

matter that has the same properties and a fixed composition. ex. gold, water, sugar

Pure substances are either elements or compounds.

Elementsa) Elements - made of

only one kind of atom. An Atom is the smallest part of an element.

Elements are found on the periodic table. ex. hydrogen (H), oxygen (O), and carbon (C)

Compoundsb) Compound - made from

more than one kind of atom.

ex. water - H2O

sucrose (sugar) - C6H12O6

A Molecule is the smallest particle of a compound that retains its properties.

Mixtures Mixtures - a blend of 2 or more

kinds of matter, each of which retains its own identity and properties.

Homogeneous Mixturealso known as a SOLUTIONa) Homogeneous mixture

(solution) – uniform (same) throughout in composition.

ex. air (a mixture of gases); brass (mixture of Cu & Zn); soda (CO2 in H2O); steel (Fe

& C)

Heterogeneous Mixture

b) Heterogeneous mixture - not uniform (different) throughout in composition.

ex. sand in water; tea with ice cubes, oil in water, chicken noodle soup

Separation of MixturesMixtures can be separated by physical

means. (See Fig 1-9)a) Filtrationb) Centrifugec) Chromatographyd) Distillatione) Crystallization

Compounds cannot be separated by physical means

Type of Matter

Classify MatterElement, Compound, Homogenous mixture, or

Heterogeneous mixture

Boric Acid Solution

Oxygen gas

Carbon monoxide (CO)

Steel (Carbon & iron)

Casserole

Homogeneous mixture

Element

Compound

Homogeneous mixture

Heterogeneous mixture

States of MatterPhase Shape Volume Fluidity

Solid Definite Definite Fixed position

Liquid Indefinite Definite Fluid

Gas Indefinite Indefinite Fluid

Solids• Definite shape.

• Definite volume.

• Vibrate about fixed positions.

• Not fluid.

Liquids• Indefinite shape.

• Definite volume.

• Vibration increases.

• Fluid.

Gases• Indefinite shape.

• Indefinite volume.

• Vibration increases.

• Fluid.

Plasma• Plasma is simply a gas,

containing charged particles such as electrons and ions.

• It is the most common state of matter in the universe.

Video: Four States of Matter

Changes of State

Temperature influences changes of state.

Solid LiquidMelting

Freezing

Liquid GasEvaporation

Condensation

Solid GasSublimation

Deposition

Liquid

Solid

Gas

S & L

L & G

SOLID LIQUID

GAS

S & LL & G

S & G

High-altitude Cooking• Did you know that the freezing and boiling

points of a substance change as the air pressure changes? At a lower air pressure, water will boil at a lower temperature. This is why cake mixes often have high-altitude directions. The lower air pressure at high altitudes allows the water in the mix to begin to turn to gas at a lower temperature. To prevent the cake from drying out, extra water is added to the mix and the oven is set to a lower temperature.

Properties of Solids• Hardness

• Elasticity

• Brittleness

• Malleability

• Tensile Strength

• Density

Hardness - measures a solid’s resistance to scratching.

Diamond is the hardest

Elasticity – measure of a solid’s ability to be stretched and return to its original size.

• This property also gives objects the ability to bounce.

• Which would you rather play basketball with?

Brittleness – measures a material’s tendency to shatter upon impact.

Malleability – measures a solid’s ability to be pounded into thin sheets.

• Example: Aluminum Foil

Tensile Strength – a measure of how much pulling, or tension, a material can

withstand before breaking.

Densityis the

amount of matter per unit volume.

m

D V

Which is heavier?

A) a pound of feathers

B) a pound of bricks

One pound = one pound

Which would take up more space?

A) a pound of feathers

B) a pound of bricks

Feathers

The density of a homogenous material will stay the same no matter how large or how small. For example, a steel paper clip and a steel bicycle.

Units for DensityMetric Units:

Solid: g/cm3

Liquid: g/ml

Density of water is 1g/cm3 at 4º C

Which one floats?• Density of Water 1.00 g/mL

• Density of Ice 0.92 g/mL

Specific Gravity

Specific gravity is the density of a substance (g/cm3) divided by the density of water (1.0 g/cm3); therefore, units will cancel out.

There are no units!

Specific Gravity =

Density of Substance

Density of Water

Which of the following will float on water?

Calculating Density• Obtain mass using a balance.

• Obtain volume by any of these methods.– Volume = length x width x height– Graduated cylinder– Water displacement

1) Is the bar really gold or fool’s gold?Gold has a density of 19.3 g/cm3

Find the density of the bar.• Mass = 1891.4 g

• Dimensions: 3.5 cm by 3.5 cm by 8.0 cm

Mass/Volume

1891.4 g / 98 cm3

= 19.3 g/cm3 Yes it’s gold!

• Mass = 16.98 g

• Volume of graduated cylinder: ?

Mass/Volume

16.98 g / 21.5 mL

= 0.79 g/mL It is alcohol!

2) Is this liquid water, alcohol, or kerosene? Find the density of the liquid? Water 1.0 g/mLAlcohol 0.79 g/mLKerosene 0.82 g/mL

3) Is this ball made of platinum, silver, or tin? Find the density of the ball. Platinum 21.5 g/cm3

Silver 10.5 g/cm3

Tin 7.3 g/cm3

• Mass = 262.5 g

• Water displaced: ?

Mass/Volume

262.5 g / 25 cm3

= 10.5 g/cm3 It is Silver!

4) What is the volume in mL of this syrup if it has a density of 0.63 g/mL and a mass of 78 g?

D

m

V

V = m/D= 78g ÷ 0.63 g/mL= 123.8 mL

5) What is the mass in grams of this lead pipe if it has a density of 11.4 g/cm3 and a volume of 55 cc?

D

m

V

m = D x v= 11.4 g/cm3 x 55 cc= 627 g

The upward force exerted on an object immersed in a fluid is called “buoyant force”.

Click on picture for demo.

Buoyancy

Draw a vector to show the buoyant force and the weight.

Weight

Buoyant Force

What is Archimedes’ Principle?

• The buoyant force exerted on an object in a liquid is equal to the weight of the fluid displaced by the object.

• Rock weighs 2.25 N• In water, the rock

weighs 1.8 N• The water displaced by

the rock weighs 0.45 N.

Do all fluids exert the same buoyant force on an object?

MercuryWhich liquid exerts a greater buoyant force?

0.45 N 0.53 N

NO

Archimedes’ Principle Demo

How Submarines Work

Click Here for Demo

Why does a block of steel sink, but a steel boat float?

Video: The Titanic Floats then Sinks

Sinks• If the weight of the

object is greater than the buoyant force, the object will sink.

• If the object has a greater density than the fluid, the object will sink.

Floats• If the weight of the

object is less than the buoyant force, the object will float.

• If the object has a lower density than the fluid, the object will float.

Why do hot air balloons float?

• A balloon will float when the weight of the balloon is less than the weight of the volume of air displaced.

• Air in the balloon is heated to make it less dense than the surrounding air.

Charles’ Law• The volume of

a gas increases with increasing temperature.

• The volume of a gas decreases with decreasing temperature.

Pressure – the force acting on a unit area of surface.

• As you pump air into a tire, the forces of all of the air particles add together to create pressure.

• Bike tire should be inflated to 60 psi (pounds per square inch)

Boyle’s Law• As the pressure

of a gas increases, its volume decreases.

• As the pressure of a gas decreases, its volume increases.

The beach ball and the basketball each contain the same amount of air.

• Which has the greater amount of pressure and why?

The basketball has greater pressure than the beach ball because it has less volume causing the air particles to have less space.

Viscosity – is the resistance to flow.

• Which flows slower?

• Molasses or Water?

How does temperature effect viscosity?

• As a liquid gets warmer, its viscosity decreases.

• Ex: cold honey vs. warm honey

• As a gas gets warmer, its viscosity increases.

• Because increasing temp increases the number of collisions thus, increasing friction.

Video Clip on Gas Viscosity