Matter States of Matter Physical and Chemical Changes Physical and Chemical Properties Separation Techniques 1 1

Classification of Matter Matter is anything that has mass and occupies space. We can classify matter based on whether it’s solid, liquid, or gas. 2 2

Classifying Matter by Physical State Matter can be classified as solid, liquid, or gas based on the characteristics it exhibits. fixed = keeps shape when placed in a container indefinite = takes the shape of the container 3 3

Solids Particles are packed close together and are fixed in position (some vibration). The close packing results in solids being incompressible. The inability of the particles to move around results in a fixed shape and volume and prevents the solid from flowing. 4 4

Crystalline Solids solids have particles arranged in an orderly geometric pattern salt diamonds sugar 5 5

Amorphous Solids Solids where the particles are randomly distributed without any clear pattern plastic glass charcoal 6 6

Liquids The particles are closely packed, but they have some ability to move around. The close packing results in liquids being incompressible. Movement of the particles allows liquids to take the shape of their container and to flow 7 7

Gases The particles have complete freedom from each other. The particles are constantly flying around, bumping into each other and the container. There is a lot of empty space between the particles. 8 8

Gases Due to empty space between particles, gases are compressible. Gases can also expand to fill and take the shape of their container, and will flow. 9 9

Learning Check State whether the following describes a solid, liquid or gas – Particles have a lot of space in between them Particles can be moved far apart or closer together Particles have the least motion The substance will fit into a square shaped and round shaped container, but cannot be compressed Particles can either be arranged orderly or randomly

Classifying Matter by Composition Another way to classify matter is to examine its composition. composition includes: types of particles arrangement of the particles attractions and attachments between the particles 11

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Classification of Matter by Composition Matter whose composition does not change from one sample to another is called a pure substance. made of a single type of atom or molecule all samples have the same characteristics. Matter whose composition may vary from one sample to another is called a mixture. two or more types of atoms or molecules combined in variable proportions different samples have different characteristics. 13 13

Classification of Matter by Composition made of one type of particle All samples show the same properties. made of multiple types of particles Samples may show different properties. 14 14

Classification of Pure SubstancesElements Pure substances that cannot be broken down into simpler substances by chemical reactions are called elements. basic building blocks of matter composed of single type of atom all known elements are listed on the Periodic Table can be abbreviated with their symbol examples – Hydrogen, Carbon, Oxygen 15 15

Classification of Pure SubstancesCompounds Substances that can be broken down are called compounds. chemical combinations of elements contain two or more different kinds of atoms all samples of a compound behave the same way. Most natural pure substances are compounds. Examples – Water (H2O), Sodium Chloride (NaCl), Ammonia (NH3) 16 16

Classification of Pure Substances made of one type of atom abbreviated by a chemical symbol 3) listed on the Periodic Table units contain two or more different kinds of atoms 2) abbreviated by a compound formula 3) made of one type of molecule, or array of ions 17 17

Classification of Mixtures homogeneous = mixture that has uniform composition throughout atoms or molecules mixed uniformly Examples – salt water, alloys, air heterogeneous = mixture that does not have uniform composition throughout atoms or molecules not mixed uniformly Examples – oil/vinegar, muddy water, granite 18 18

Classification of Mixtures made of multiple substances, whose presence can be seen Portions of a sample have different composition and properties. made of multiple substances, but appears to be one substance Portions of a sample have the same composition and properties. 19 19

Learning Check Identify each of the following as an element, compound, homogeneous or heterogeneous mixture - Gasoline A stream with gravel at the bottom Air Brass Copper Maple syrup Oxygen and helium in a scuba tank Oil and vinegar salad dressing Table salt

Changes in Matter Changes that alter the state or appearance of the matter without changing its identity are called physical changes. Changes that alter the identity of the matter are called chemical changes. 21 21

Physical Changes in Matter The boiling of water is a physical change. The water molecules are separated from each other, but their structure and composition do not change. 22 22

Common Physical Changes Irreversible breaking, cutting, grinding Reversible state changes boiling/condensing melting/freezing Subliming dissolving CO2(s) CO2(g) Dry Ice Subliming of Dry Ice Dissolving of Sugar C12H22O11(s) C12H22O11(aq) 23 23

Chemical Changes in Matter Rusting of iron is a Chemical Change Iron and Oxygen (O2) form rust (Iron Oxide) 24 24

Common Chemical Changes Signs of a Chemical Change Color change Gas Production Heat Transfer Formation of a precipitate C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(l) 25 25

Learning Check Identify each of the following as a physical or chemical change - Iron metal is melted Iron combines with oxygen to form rust Wood burns in air A rock is broken into small pieces Milk turns sour Wax is melted over a flame and then catches fire and burns

Properties of Matter Physical properties are the characteristics of matter that can be observed without changing its identity. Color, density, melting/boiling points Chemical properties are the characteristics that determine how the composition of matter changes as a result of contact with other matter or the influence of energy. Will it rust?, burn?, tarnish? 27 27

Learning Check Identify each of the following as a physical or chemical property - The boiling point of a certain alcohol is 78oC Diamond is very hard Sugar ferments to form alcohol A meta wire conducts electrical current Gallium metal melts in your hand Platinum does not react with oxygen at room temperature The slide background is white The copper on the Statue of Liberty has acquired a green coating

Separation Techniques When two or more materials or substances are mixed together but do not chemically combine. This means they retain their original properties. This means they can be separated by physical means.

What are the different ways of separating mixtures? Magnetism Hand separation Filtration Sifting or sieving Extraction and evaporation Chromatography

Magnetism If one component of the mixture has magnetic properties, you could use a magnet to separate the mixture. Iron, nickel, and cobalt are all materials that are magnetic. Not all metals are magnetic: gold, silver, and aluminum are examples of metals that are not magnetic.

Hand separation Separating the parts of a mixture by hand. Only useful when the particles are large enough to be seen clearly. Useful for: separating parts of a salad.

Filtration Used when separating a solid substance from a fluid (a liquid or a gas) by passing a mixture through a porous material such as a type of filter. Works by letting the fluid pass through but not the solid. Examples of filters: coffee filter, cloth, oil filter, even sand!

Sifting or sieving Used to separate a dry mixture which contains substances of different sizes by passing it through a sieve, a device containing tiny holes.

Extraction Used to separate an insoluble solid (something that doesn’t dissolve in a liquid) from a soluble solid (something that DOES dissolve in a liquid). Done by adding a solvent (liquid that does the dissolving) to the mixture. Then pouring the liquid through a filter.

Distillation/Evaporation Allowing the liquid to evaporate, leaving the soluble solid behind. Example: heating sugar water. The water evaporates and the sugar crystals are left behind.

Chromatography Used to separate dissolved substances in a solution from each other. Mixture Components Separation Stationary Phase Mobile Phase

Learning Check Identify the best separation technique to be used in each situation - Paperclips and confetti Pebbles and sand Components of a watercolor marker Cooked pasta and water Dissolved salt and water Components of a sandwich