Matter A Review Has mass Takes up space ex. Chemistry is the study of MATTER! Topic 4.D - Classifying Unit 1 Organizing Matter 2011 Classifications of Matter Mixtures Contain more than one kind of matter Matter Anything that has mass and takes up space Substances Cannot be separated into different kinds of matter by physical means Mixtures Contain more than one kind of matter Can be separated physically a. Sorting b. Filtering c. Heating and cooling Homogeneous Mixture Same throughout Heterogeneous Mixture Varies in content Element All atoms are the same Compound Consists of two or more types of atoms Types of Mixtures a. Homogeneous mixtures are the same throughout; every sample has the same ratio of ingredients Ex: milk b. Heterogeneous Mixtures vary throughout; each sample has the may have a different ratio from the next Ex: chicken soup Mixture Examples Petroleum (Crude Oil) 1,000,000 molecular compounds Soda Carbonated water, corn syrup, caramel color, phosphoric acid, natural flavors and caffeine Paint Pigment, Latex, thinning agents 1
Pure Substances Cannot be separated by physical means May contain more than one kind of matter held together by chemical bond examples: Lithium, NaCl Types of Substances a. Elements Contain only one kind of matter; (one kind of atom) b. Compounds contain two or more elements; can be separated chemically Topic 4.B - Properties of Matter Unit 1 Organizing Matter - 2011 Intensive vs. Extensive Intensive properties: characteristics that do not depend on the amount of matter present. example: density Extensive properties: characteristics that depend on how MUCH matter is present example: mass Intensive Properties Properties that do not change depending on how much stuff you have. These are observable whether you have a lot or a little of it. For example, a diamond will be sparkly and lustrous no matter if it is tiny or giant. Extensive Properties Properties that change depending on how much stuff you have. These will change if you have a small amount or if you have a large amount. For example, a small sample of sand will have less mass than a large sample of sand. 2
Types of Physical Properties Something you can observe or measure without changing the matter into something else. For example, you can measure how much something weighs or what it smells like without changing it into something else. You cannot tell if something will burn without changing it into something else. 1. Density how tightly packed the particles are in a substance ( compactness ) The relationship of mass to volume 1. Density (contd.) 2. Viscosity Less dense = float More dense = sink example: substances that are less dense than water will float on water. resistance to flow Viscous fluids are thick and hard to pour Large molecules flow more slowly (MORE VISCOUS) Small, smooth molecules flow more quickly (LESS VISCOUS) 3. Malleability A solid s ability to be pounded into thin sheets 5. Conductivity The ability of a material to conduct electricity, heat, or sound 4. Ductility the ability to be made into wire 3
6. Melting Point 8. Luster temperature at which a solid melts to beome a liquid 7. Boiling Point temperature at which a liquid boils to become a gas how much the surface of a material reflects light ( shine ) example: chrome 9. Solubility the ability of one substance to be dissolved in another substance solubility can depend on temperature, pressure, and how much of each substance is interacting Types of Chemical Properties The ability of something to react with something else or to change into something else. You cannot observe chemical properties without changing the object into something else. For example, if you observe that a nail will rust, it has already changed into rust. Reactivity Describes how readily a substance will undergo a chemical reaction with another substance Toxicity The degree to which a substance can damage an organism Copper Reacts with Nitric Acid Magnesium Reacts with Hydrochloric Acid 4
Corrosiveness Flammability A measure of how much a substance can destroy or irreversibly damage another surface or substance with which it comes into contact. Often strong acids and bases. How easily something will burn or ignite Physical vs. Chemical Topic 4.A - Changes in Matter Unit 1 Organizing Matter - 2011 Physical change - same substance before and after Chemical Change make a new substance Physical Changes Affect only physical properties: size shape state Examples of Physical Changes Shattering glass Crushing ice Letting ice melt Compressing a gas dissolving 5
Phase Changes (a.k.a. changes of state) Phases or states are: solid, liquid, gas (and plasma) changes from one state of matter to another based on the addition of or loss of energy (heat or thermal energy) Phase Changes (a.k.a. changes of state) Melting: solid to liquid Boiling or Evaporation: liquid to gas Condensation: gas to liquid Freezing: liquid to solid Sublimation = solid straight to gas! Chemical Changes The result of chemical reactions Bonds must be broken and/or created to form a new substance(s) How do you know if a chemical change has occurred? Product is obviously different than starting materials Energy has been released or absorbed (careful did you add the energy?) Obvious changes in: Color Texture Opaqueness Gas bubbles form (not boiling!) Phases of Matter Topic 4.C Phases of Matter Unit 1 Organizing Matter - 2011 gas liquid solid most movement (high kinetic energy) shape and size is dependent on the container a liquid is in Fluids Molecules can be compressed closer together least dense phase shape and size is dependent on the container a liquid is in Fluids molecules are touching, but slide around each other molecules are touching and vibrate in place solids have a definite shape and size 6