Chemistry Chapter 3 Properties and Classification of Matter Chemistry- Matter and Change Glencoe Last revision Fall 2007

Matter Matter – anything that has mass and volume. Mass – the amount of material that makes an object Volume – the amount of space an object takes up Light from a lighthouse? The pen/pencil you are writing with? Your textbooks? Your thoughts? Heat from a fire?

All matter is made of tiny little particles called atoms. There are 90 different naturally existing atoms and 25 man made ones. They can all be found on the periodic table. 2 hydrogen atoms & 1 oxygen atom 1 sodium atom & 1 chlorine atom. Everything about you and everything around you is made of these atoms or combinations or mixtures of these atoms. Salt (NaCl) For example: Water (H 2 O)

Properties of Matter Physical Property - a quality or condition of matter that can be observed or measured without changing the arrangement of atoms that make it Examples: color size shape state of matter texture These properties can usually be observed using our senses or measured with equipment in the lab. Mass Length Volume Boiling point Melting point

Chemical Properties – property that can only be observed when the arrangement of particles that make the matter are altered These properties usually tell you how a substance will react in the presence of a second substance. Examples: Iron reacts with oxygen to form rust. Metals react with acids to form hydrogen gas.

Changes in Matter Physical Changes – changes in matter that do not alter the arrangement of atoms that make the matter Changes in size, shape, and STATE OF MATTER. Examples: crumpling up a piece of paper breaking a stick in half melting ice salt dissolving in water

Think about water. Everyone knows the arrangement of atoms that make water: If water is frozen into ice, what is the arrangement of atoms that make the ice? Once the ice melts it is water again. What is the arrangement of atoms? If the water is heated and it boils turning to steam, what is the arrangement of atoms? H2O H2O H2O H2O H2O H2OH2O H2O H2O H2O H2O H2O H2O H2O H2O H2O

Chemical Changes - changes in matter that DO alter the arrangement of atoms that make the matter Because you can’t see the particles to determine if arrangement has changes, you can look for clues that tell you a chemical change has occurred. Clues of a Chemical Change:  color change  production of a solid  production of a gas  release of heat, light, or sparks

Identify the following as either a physical property or a chemical property. PropertyPhysicalChemical a shirt is red sodium is so soft it can be cut with a knife potassium reacts vigorously with water paper is flammable water boils at 100 o C √ √ √ √ √

Identify the following as either a physical change or a chemical change. ChangePhysicalChemical burning toast breaking a glass melting butter leaves changing color fireworks exploding √ √ √ √ √

Intensive vs. Extensive Intensive properties are properties unique to a pure substance. It is a property that can be used to identify it. Ex: Density, boiling point, melting point, odor Extensive properties are properties that many kinds of substances can have and will not identify the substance. Ex: Mass, volume, shape

Now that we can describe matter, we can begin to classify it Matter-anything with mass and volume Matter is separated into two categories: pure substances and mixtures. Matter Pure Substance Mixtures

Pure Substance – a substance made of the same kind of atoms or compounds having a unique set of chemical and physical properties The two categories of pure substances are elements and compounds Pure Substance Element Compound

Element simplest type of pure substance made of only 1 kind of atom Examples: Hydrogen (H 2 ) Oxygen (O 2 ) Carbon (C) all particles are identical cannot be separated by a physical or a chemical change Diatomic molecules are still elements. H. BrONCl I F

Compounds made of two or more different kinds of elements chemically combined together in a specific ratio Examples: H 2 O - Water H 2 O 2 - Hydrogen Peroxide NH 3 - Ammonia elements in a compound can only be broken apart by a chemical change

Classify the following as either an element or a compound.

Mixtures physical blend of two or more pure substances. can be separated by a physical change The two categories of mixtures are homogeneous and heterogeneous. Mixtures Homogeneous Heterogeneous Mixtures Mixtures

Homogeneous Mixtures mixtures that are uniform in composition on the atomic level. all parts of the mixture have the same concentration of matter. Different parts of the mixture can not be identified (transparent appearance for solutions) Alloys: solution of metal also called a solution Examples: Salt water, vinegar Lemonade, alcohol 3% H 2 O 2 and H 2 O solution Steel, solder or 14 K gold

Heterogeneous Mixtures mixtures that are not uniform in composition all parts of the mixture are not the same the different parts can usually be easily identified from one another Examples: rocks and sand salt and pepper oil and water Pizza

Classify the following as either a homogeneous mixture or a heterogeneous mixture.

Classify the following everyday common objects as a homogeneous mixture or a heterogeneous mixture. Jelly Pizza Soda Lotion Chunky Peanut Butter Mixed Nuts

Matter Pure Substances Mixtures Element Compound Homogeneous Heterogeneous

State of Matter- Matter can be solid, liquid, gas or plasma depending on how much kinetic energy (or motion) they have. Solid: Particles vibrate in place. It has a definite volume and a definite shape. Liquid: Particles roll around each other. It has a definite volume but no definite shape. Gas: Particles move around colliding with one another. It has no definite volume or shape. Plasma: Particles are so hot and excited that the electrons leave the nucleus and matter is ionized or charged

Matter in Motion The Kinetic Molecular Theory states that atoms and molecules are always in motion. Remember, the temperature of a substance is the measure of its kinetic energy. That energy can only do one thing at a time: 1.Change the state of the substance. 2.Increase the temperature of a substance.

Depositing SublimatingFreezing Boiling Condensing Melting 1. Changes in the states of Matter

2. Heating Curve This curve can also work in reverse if energy is being taken away.

Absolute Zero is the temperature at which all motion of particles stops. Scientists have yet to reach it.

Separating Mixtures Mixtures are physical blends of two or more pure substances. Since they are mixed physically, they can be separated into the individual pure substances by physical changes.

   Contrast Compare Contrast physical blend of two or more pure substances can be separated by physical changes all parts are not the same the different parts of the mixture can usually be easily identified or it is opaque or translucent all parts are the same different parts of the mixture can not be identified from one another. Compare and Contrast the two types of mixtures. It is transparent (unless it is an alloy or mixture of metals)

Distillation - method of separating components of a solution using their boiling points. involves 3 stages and both are state of matter changes  The solution is boiled to vaporize one component of the solution with the lower boiling point.  As soon as the temperature starts to rise, the vapor stops being collected since this rise in temperature indicates the end of a phase change.  The vapor is cooled to turn it back into a liquid Methods of Separating Mixtures using: Freezing and Boiling Points Example: Separate alcohol and water

 Dissolve substance that is soluble in water.  Filtration - uses a filter of porous material to separate a mixture of liquid and insoluble components  Evaporate the liquid portion of a solution which changes to a gas or vapor leaving a solid behind Solubility Example: Separate sand and salt.

Magnetism - used to separate components of a mixture when one is attracted to a magnet and one is not Chromatography - method of separation used to see what colors make up an ink or substance containing different molecules. Steps of Chromatography 1. Material to be separated is spotted on chromatography paper 2. Paper is dipped into a solution that will be absorbed by the paper and moves up 3. Some colors move more than others and separate