Chemistry Mrs. Algier Do Now: Explain 1 instance from over the weekend that you can relate to Chemistry SAFETY QUIZ YWBAT Differentiate between extensive and intensive properties Differentiate between the states of matter Describe each object Properties What you observe when you look at a particular sample of matter is its properties. Is it a solid or liquid? Is it shiny or dull? Does a liquid flow quickly or slowly? Is a gas odorless, or does it have a smell? Physical Property Characteristic that can be observed or measured WITHOUT changing the substances composition Examples State (Solid, Liquid, Gas) Color Melting Point Physical Properties Mass Measure of the amount of matter an object contains. Volume Measure of the space occupied by an object. Density Ratio of the mass of an object to its volume. Physical Properties 1. Calculate combined mass 2. Calculate combined volume 3. Calculate combined density Physical Properties Intensive Does NOT depend on the amount of matter. Extensive Depends on the amount of matter. Classify as Extensive or Intensive Mass Melting Point Color Volume Boiling Point Concentration Length Freezing Point Temperature Density Physical Properties Intensive Does NOT depend on the amount of matter. Examples: Melting/Freezing Point Boiling Point Density Concentration Temperature Extensive Depends on the amount of matter. Examples: Mass Volume Length Physical Properties of Matter Identifying a Substance Substance Matter that has a uniform and definite composition Every sample of a given substance has identical intensive properties because every sample has the same composition. Identifying a Substance A colorless substance that boils at 100 deg C and melts at 0 deg C is _____. A colorless substance that boils at 78 deg C and melts at -117 deg C would be _______. States of Matter Solids Liquids Gases Solids A solid is a form of matter that has a definite shape and volume. the shape of a solid doesnt depend on the shape of its container The particles in a solid are packed together, often in an orderly arrangement Solids A solid is a form of matter that has a definite shape and volume. As a result, solids are almost incompressible; it is difficult to squeeze a solid into a smaller volume Solids expand only slightly when heated Liquids A liquid is a form of matter that has an indefinite shape, flows, and has a fixed volume. A liquid takes the shape of the container in which it is placed. Volume does NOT change as shape changes Gases A gas is a form of matter that takes both the shape and volume of its container Gases vs. Vapor The terms vapor and gas are sometimes interchanged, but technically there is a difference. Gas used for substances that exist in the gaseous state at room temp (for example, oxygen) Vapor describes the gaseous state of a substance that is generally a liquid or solid at room temperature (for example, water vapor) Gases The particles in a gas are generally much further apart than the particles in a liquid. Because of the space between particles, gases are easily compressed into a smaller volume. Physical Changes During a physical change, some properties of a material change, but the composition of the material does not change. Examples Boil, freeze, melt, condense Break split, grind, cut, crush Physical Changes can be reversible or irreversible