Definition:

Anything that contains mass and occupies space (volume.)

Matter

Pure Substances

Mixtures

Elements

Compounds

Homogeneous

Heterogeneous

Draw this chart!, Draw this chart!, leave space to leave space to define the termsdefine the terms

Mixtures and Pure Substances

A pure substance is made of only one kind of material and has definite properties.

Matter that consists of two or more substances mixed together but not chemically combined is called a mixture.

Pure Substances:

Elements are the simplest pure substance.

Examples: hydrogen, carbon, and oxygen.

The smallest particle of an element that has the properties of that element is called an atom.

Pure substances:

Compounds are pure substances that are made of more than one element bound together.

Examples: water (H2O), and carbon dioxide.

A molecule (or a Formula Unit) is formed when two or more atoms combine.

Example: water (H2O), O2

MIXTURESHeterogeneous vs. Homogeneous

Homogeneous matter (solutions): matter that has identical properties throughout.

Examples: Salt water, and whipped cream

Heterogeneous matter: matter that

has parts with different properties.Examples: granite, soil, potpourri

EXAMPLES

• What type of matter are each of the following… ?

SAND

SAND

Heterogeneous mixtureHeterogeneous mixture

Salt (NaCl)

Salt (NaCl)

COMPOUNDCOMPOUND

Air

Air

• Homogeneous mixture of: Nitrogen, N2 78.08%Oxygen, O2 20.95%Argon, Ar 0.93%Carbon dioxide, CO2 0.033%Neon, Ne 0.0018%Helium, He 0.00052%Methane, CH4 0.0002%Krypton, Kr 0.00011%Nitrogen(I) oxide, N2O 0.00005%Hydrogen, H2 0.00005%Xenon, Xe 0.0000087%Ozone, O3 0.000001%

Many gases make up mixture, Many gases make up mixture, but it looks like it is all one but it looks like it is all one gas.gas.

Gold

GoldELEMENT: AuELEMENT: Au

Bronze

Bronze

Homogeneous Homogeneous mixturemixture of of copper and tin copper and tin (alloy: mixture (alloy: mixture of metals)of metals)

Salad Dressing

Salad Dressing: Heterogeneous

Conservation

Law of Conservation of Matter (Mass): Matter cannot be created or destroyed.

Law of Conservation of Energy:Energy cannot be created or destroyed; it may only change from one form to another.

Matter and energy MUST be conserved; it’s the LAW!

Virtually everything that is, is made up of atoms.

From the very large...

To the very small...

We are all made of atoms…and only atoms.

This includes you and me!

Making stuff nature

never dreamed of.

The Elements Song

Currently we know about 115 different atoms. In the natural world there are 88 different atoms.

The others have been artificially produced in laboratories.

We call each kind of atom an element, and give it a specific name and symbol.

Copper Cu

Gold Au

Periodic Table

Abundance of the elements, by

weight

The Earth’s interior is rich in iron

Sand is made of

Silicon & Oxygen

The ocean waters are made of

oxygen & hydrogen

Atoms are made up of protons, neutrons, and electrons.

Protons and neutrons are found in the nucleus of atoms -- roughly at the center

Electrons travel around the nucleus.

Of course real atoms don’t look anything

like this!

Different kinds of atoms, or elements, are different because they have different numbers of protons.

They don’t look anything like this

either!

We list the elements by their atomic numbers - the

number of protons they have.

Hydrogen, number 1 Helium, number 2

In several cases the atomic weights are in parentheses.  This indicates that these elements have no stable isotopes; that is, they are radioactive.  The value In several cases the atomic weights are in parentheses.  This indicates that these elements have no stable isotopes; that is, they are radioactive.  The value enclosed in parentheses and used for the atomic weight is the atomic mass number of the most stable known isotope, as indicated by the longest half-life. enclosed in parentheses and used for the atomic weight is the atomic mass number of the most stable known isotope, as indicated by the longest half-life.

Physical Properties

Physical properties: characteristics that can be observed without changing the identity of the substance.

Examples: – mass– volume– color – shape – texture– density

Physical Changes

Physical change: a change in the physical form or properties of a substance that occurs without a change in composition.

Examples:– melting– freezing– grinding– dissolving

Chemical Properties

Chemical property: describes a substance’s ability to change into a different substance.

Examples: – flammability– reactivity– health benefits– health hazards

Chemical ChangesChemical change occurs when a substance changes composition by forming one or more new substances. (bonds are broken and bonds are formed)

Example:HCl + NaOH NaCl + H2O

Indications of a Chemical Change…

Flames

Gas is given off (evoloved)(not to be confused with boiling)

Color Change

Evaporation is a physical change

Breaking is a physical change.

Boiling is a change of state, and therefore a

physical change!

Rusting is a Chemical Change

Burning is a Chemical Change

• NOTETAKERS:

• PHASES of MATTER

• Kinetic Molecular Theory

Kinetic Moleuclar Theory

All matter is made of atoms and molecules that act like tiny particles.

These tiny particles are always in motion. The higher the temp., the faster the particles move.

At the same temp., more massive (heavier) particles move slower than less massive (lighter) particles.

SOLIDS

Definite shape?YES

Definite volume?YES

Molecules in a solid are tightly packed and constantly vibrating at any temperature above absolute zero = 0.00 K

LIQUIDS

Definite shape?NO

Definite volume?YES

Some liquids flow more easily than others. The resistance of a liquid to flow is called viscosity.

– Honey has a high viscosity compared to water.

GASES

Definite shape?NO

Definite volume?NO

The particles in a gas are spread very far apart, but can be compressed by pumping them into a restricted volume.

Phase Changes (Changes of State)

• Changes in phase are examples of physical changes.

• Melting: solid liquid• Freezing: liquid solid• Vaporization: liquid gas• Condensation: gas liquid• Sublimation: solid gas• Deposition: gas solid

Changes of State

GAS

SOLID

Deposition

Sublimation

VaporizationCondensation

Melting

Freezing

LIQUID

Melting

ENERGY is the ability to change or move matter.

Energy is ABSORBED when substances melt or evaporate.NOTE: our bodies cool down when our sweat evaporates.

Energy is RELEASED when substances freeze or condense.

Melting

The change of state from solid to liquid.

Energy (heat) is absorbed by the substance that is melting.

FreezingThe change of state from liquid to solid. Freezing is the opposite of melting.

Energy (heat) is released by the substance that is freezing.

EvaporationThe change of state at the surface of a liquid as it passes to a vapor. This results from the random motion of molecules that occasionally escape from the liquid surface.

Energy (heat) is absorbed by the liquid

This can happen at any temperature.

Condensation

The change of state from gas to liquid. The opposite of evaporation.

Energy (heat) is released by the gas to become a liquid.

BoilingChange from state from a liquid to a gas.

Occurs throughout the liquid.boiling point/temperature is determined by pressure

Energy (heat) is absorbed by the liquid for it to boil and produce gas.

*Boiling & freezing points depend on the pressure.*Boiling & freezing points depend on the pressure.

Water at normal pressure (1 atm):

For water at normal (every day) pressures:

Melting/freezing point:

Condensing/boiling point:

0 oC (32oF)

100 oC (212oF)

Label the points & temperatures on your graph.

*Boiling & freezing points depend on the pressure.*Boiling & freezing points depend on the pressure.

00°C°C

100°C100°C

*Boiling & freezing points depend on the pressure.*Boiling & freezing points depend on the pressure.

00°C°C

100°C100°C

Potential Energy = flat lines (stored energy)

*Boiling & freezing points depend on the pressure.*Boiling & freezing points depend on the pressure.

00°C°C

100°C100°C

Kinetic Energy = slanted lines (energy of motion, temperature is changing)

Change the pressure Change the Boiling Point

Phase Diagrams• a phase diagram shows the equilibria

pressure-temperature relationship among the different phases of a given substance

Draw Phase Diagrams

Water CO2

Label SOLID, LIQUID, GAS phases

Label points A, B, C, D (show on board)

triple point = Point ______The point at which all 3 phases of a substance (solid, liquid, gas) can coexist at equilibrium.

critical point = Point ______The combination of critical temperature and critical pressure.

A

C

D

critical temp = temp. above which a gas cannot be liquefied. (H2O=374ºC)

critical pressure = press. required to liquefy a gas at its critical temperature. (H2O=218 atm)

AB = AC = AD =

C

WATERWATER Carbon DioxideCarbon Dioxide

AB = AC = AD =

C

meltingcurve

AB = AC = AD =

C

meltingcurve

sublimationcurve

AB = AC = AD =

C

meltingcurve

sublimationcurve

vaporpressurecurve