Classification of Matter Unit 3 – Study of Matter *

What is Matter? Matter What are some examples of matter? The “stuff” that makes of the universe Anything that has mass and takes up space What are some examples of matter? *

Properties of Matter Name some properties of the puppy… Each specific substance has its own combination of properties that can be used to identify the substance Chemistry The study of the properties of matter and how matter changes Chemistry The study of the properties of matter and how matter changes *

Properties of Matter Properties Color Hardness Texture Shape white, green... Hardness hard, soft... Texture smooth, rough, slippery... crystal, powder... Shape square, no shape… State of Matter solid, liquid, gas Temperature by observation only! hot, cold… Properties of Matter *

Properties of Matter Flammability Solubility Odor Density - How easily does it catch on fire, MSDS Sheet Solubility - ability of a given solute (solid) to dissolve in a solvent (liquid) Odor - does it have a smell? Density - amount of mass per volume Melting/Boiling Point - at what temperature does it melt or boil Viscosity - resistance for a liquid to flow - flows slow = high viscosity Malleability - ability for a material to bend

Kinds of Matter 3 kinds of matter Identify which is which… Elements Compounds Mixtures Identify which is which… *

A substance that can not be broken down into any other substances by chemical or physical means Smallest part that keeps it’s properties Building blocks of matter All matter composed of elements Elements are made of atoms Exist in uncombined and combined forms Elements *

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Compounds A substance made of two or more elements chemically combined Formulas CO2 Two O for every 1 C How do compounds differ from elements? *

Mixture Made from two or more substances that are together in the same place but NOT chemically combined into a new substance Elements, compounds, or both Water Not found in pure state in nature Found as mixture that contains dissolved oxygen, salts, and other substances *

Mixture Heterogeneous Homogeneous Not uniform in composition Can tell the difference between the substances Possible to separate Homogeneous Uniform in composition Can NOT tell the difference between the substances Difficult to separate also called a solution Mixture *

Solutions Some mixtures involve solids being dissolved in a liquid koolaid Solute solid substance to be dissolved Solvent liquid that will be doing the dissolving Solution mixture of the solute being dissolved in the solvent

Solutions A cup of water can only dissolve so much salt solvents can only dissolve a certain amount of solute the rest will settle in the bottom saturated Temperature changes this The warmer the solvent, the more solute it can dissolve The particles have more kinetic energy and can overcome more attractive forces

The Beach Elements Compounds Silicon, oxygen, calcium, carbon Calcium carbonate, silicon dioxide How is silicon different from silicon dioxide? How is calcium carbonate different from calcium, oxygen, and carbon? How to the properties of the beach sand, which is a mixture, compare to the properties of the compounds it contains? Mixture *

Changes in Matter Is this someone you know?? How can you tell? Two ways matter can Change: Physical Change Chemical Change *

A change that alters the form or appearance of a material but does NOT convert the material into a new substance Examples Chopping wood Bending wire Changes in state Physical Change *

Physical Change Change of State Still the same substance changing from one phase of matter to another solid - liquid - gas Still the same substance

Chemical Change A change in matter that produces new substances (aka chemical reaction) Made from the same elements Rearranged into new combinations Examples Burning Rusting *

Physical vs. Chemical Change Physical Change stampedes → stampedes Chemical Change stampedes → made + steps Chemical vs. Physical Changes *

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Solid Definite shape and definite volume Particles are packed very close together Stay together in fixed positions Vibrate (move back and forth slightly) Low kinetic energy Not easily compressed or expanded *

Liquid Definite volume, no definite shape Particles are free to move Slightly more kinetic energy than a solid Packed almost as close as a solid Takes the shape of its container Do not easily compress or expand Just changes shape *

Viscosity Resistance of a liquid to flow High viscosity flow slowly Molasses syrup Low viscosity flow quickly Water Rubbing alcohol Vinegar *

Gas No definite shape or volume Will spread or squeeze to fit the container Move quickly and randomly - high kinetic energy Like seagulls *

Energy and Changes in State Thermal energy Energy of the particles of a substance Gain thermal energy – move faster (endothermic) solid to liquid to gas Lose energy – move slower (exothermic) gas to liquid to solid Change of state occurs when thermal energy increases or decreases by a sufficient amount *

Changes in State *

Liquid and Solid Melting Freezing All happens at 0°C for water Solid to liquid Energy added changes the arrangement of the molecules Molecules vibrate faster and faster and break free Freezing Liquid to solid Energy lost Molecules move so slowly they form regular patterns All happens at 0°C for water *

Liquid and Gas Vaporization Condensation Liquid gains energy to become a gas Two types Evaporation – only takes place on the surface Drying puddle Boiling – takes place inside and on the surface Boiling point – temperature at which a specific liquid boils Changes with air pressure – Denver, Colorado (lowers) Condensation Gas particles lose energy to become a liquid Breathing on a mirror *

Identifying Substances 3 unknown clear colorless materials Determine the difference based on boiling points Water: 100°C Chloroform: 61°C Ethyl alcohol: 79°C *

Solid and Gas Sublimation Deposition Solid gains energy to become a gas Does not pass through liquid phase at all Deposition Gas loses energy to become a solid With dry ice, you can’t see the gas that forms… the fog is water vapor from nearby air that cools *

Density As thermal energy is added particles move faster spread out more Density decreases as thermal energy increase Density = mass per volume D=m/V Volume space it takes up *