ANYTHING WITH MASS AND VOLUME. Matter Pure Substances Mixtures Elements Compounds Homogeneous Heterogeneous Draw this chart!, leave space to define the.

ANYTHING WITH MASS AND 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

Pure Substances vs. Mixtures

• 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 is formed when two or more atoms chemically combine.

Example: water (H2O), O2

MIXTURESHeterogeneous vs. Homogeneous

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

Heterogeneous matter: matter that has parts with different properties.

Examples: salt water, gravy, whipped cream

Examples: granite, soil, potpourri, cookies

LIQUID MIXTURESMiscible vs. Immiscible

• Miscible Mixture: liquids that mix evenly, forming a homogeneous solution. Example: Soda mixed with Koolaid

• Immiscible Mixture: liquids that DO NOT mix evenly, forming a heterogeneous mixture. Example: Oil mixed with Water

EXAMPLES

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

SAND

SAND

Heterogeneous mixtureHeterogeneous mixture

Salt (NaCl)

Salt (NaCl)

Pure Substance: COMPOUNDPure Substance: COMPOUND

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 gas.but it looks like it is all one gas.

Gold

GoldPure Substance: Pure Substance: ELEMENT: 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 MixtureHeterogeneous Mixture

Conservation

• Law of Conservation of Mass: Mass 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

is the LAW!

Virtually everything 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!

Giggitty, Giggitty, Goo!

The Elements Song

Currently we have about 117 kinds of atoms. In the natural world there exists 92 different kinds of 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 you imbecile!

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

It would be sweet if atoms really were this

huge!

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

Chemical Changes• Chemical 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…

Heat in Endothermic (feels cold)

Heat out Exothermic (feels hot)

Gas is given off (fizzing or bubbles)

Color Change

New Substance is Formed

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

Kinetic 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. (inertia)

SOLIDS

• Definite shape?• YES

• Definite volume?• YES

• Molecules in a solid are tightly packed and constantly vibrating.

Eureka: Molecules in Solids

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.

Eureka: Molecules in Liquids

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.

Eureka: Molecules in Gases

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.

Energy Transfers

Melting

• The change of state from solid to liquid.

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

Freezing• The change of state from liquid to

solid. Opposite of melting. • Energy (heat) is released by the

substance undergoing freezing.

Evaporation• The 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

– 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.

Boiling• Change 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)

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

00°C°C

100°C100°C

Change the pressure Change the Boiling Point