MATTER ANYTHING WITH MASS AND VOLUME

Classification of Matter Elements Draw this chart!, leave space to define the terms Pure Substances Compounds Matter Homogeneous Mixtures Heterogeneous

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 is formed when two or more atoms combine. Example: water (H2O), O2

MIXTURES Heterogeneous vs. Homogeneous Homogeneous matter (solutions): matter that has identical properties throughout. Examples: Sugar, 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 mixture

Salt (NaCl)

Salt (NaCl) 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% Homogeneous mixture of: Many gases make up mixture, but it looks like it is all one gas.

Gold

Gold ELEMENT: Au

Bronze

Bronze Homogeneous mixture of copper and tin (alloy: mixture 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...

This includes you and me! We are all made of atoms…and only atoms. This includes you and me!

Making stuff nature never dreamed of. Currently we have about 115 kinds of atoms. In the natural world there exists 88 different kinds of atoms. The others have been artificially produced in laboratories. Making stuff nature never dreamed of. The Elements Song

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

Of course real atoms don’t look anything like this! Atoms are made up of protons, neutrons, and electrons. Protons and neutrons are found in the nucleus of atoms -- roughly at the center Of course real atoms don’t look anything like this! Electrons travel around the nucleus.

They don’t look anything like this either! 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. Helium, number 2 Hydrogen, number 1 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.

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… Flames Gas is given off (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 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? Molecules in a solid are tightly packed and constantly vibrating.

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? 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 SOLID GAS LIQUID Melting Vaporization Condensation Deposition Sublimation Vaporization Condensation Melting Freezing LIQUID

ENERGY TRANSFERS!!! 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.

Freezing The change of state from liquid to solid. Opposite of melting. Energy (heat) is released by the substance undergoing freezing.

Evaporation Energy (heat) is absorbed by the liquid 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.

Phase Change Graph *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.

Phase Change Graph 0°C 100°C *Boiling & freezing points depend on the pressure.

Phase Change Graph Potential Energy = flat lines (stored energy) 0°C *Boiling & freezing points depend on the pressure.

Phase Change Graph Kinetic Energy = slanted lines (energy of motion, temperature is changing) 100°C 0°C *Boiling & freezing points depend on the pressure.

Change the pressure  Change the Boiling Point

VIDEO Bill Nye: Phase Changes

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)

A D triple point = Point ______ C A triple point = Point ______ The point at which all 3 phases of a substance (solid, liquid, gas) can coexist at equilibrium. D critical point = Point ______ The combination of critical temperature and critical pressure. 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)

WATER Carbon Dioxide C AD = AB = AC =

C melting curve AD = AB = AC =

C melting curve sublimation curve AD = AB = AC =

C vapor pressure curve melting curve sublimation curve AD = AB = AC =

Activity Triple Point of Carbon Dioxide