UNIT 2 Describing Substances Mixtures & Compounds

 Chose any object in the room and draw a particle model of that object.  Do you think the object you drew is made up of only one type of particle?  How do we classify different types of matter?

CLASSIFICATION OF MATTER  As a group categorize the 10 substances around the room.  Think about something that we categorize/classify  What characteristics do we use?  What characteristics could you use to categorize the items presented?

IDENTIFYING ELEMENTS, COMPOUNDS & MIXTURES

MATTER SUBSTANCE MIXTURES Can write chemical formula, homogeneous Variable Ratios COMPOUNDELEMENT HETEROGENEOUSHOMOGENEOUS

ElementCompoundMixture Made of 1 kind of atom (found on the periodic table) Cannot be separated into any simpler form chemically or physically Made of 2 or more kinds of atoms chemically combined in a certain ratio (example: water molecule is 2 Hydrogens and 1 Oxygen atom) 2 or more elements or compounds mixed together physically Not chemically combined!!! Each part keeps its own chemical identity Can be heterogeneous (different throughout) or homogeneous (same throughout)

SubstanceClassification (Element, Compound, Heterogeneous or Homogeneous Mixture) How do you know? 1.Chlorine 2.Water 3.Soil 4. Sugar Water 5.Oxygen 6. Carbon Dioxide 7. Rocky Road Ice Cream 8.Alcohol 9. Pure Air 10. Iron

Pre lab Questions 1.What is the difference between an element and a compound? 2.How is a heterogeneous mixture different from a homogeneous mixture? 3.How is the way a mixture is combined DIFFERENT from how a compound is combined? 4.What is easier to separate, a mixture or a compound? Why? 5.Which can be found on the periodic table: elements, compounds, or mixtures?

Station #/ Identity of Substance Description/ObservationsClassification (Element, Compound, Mixture) How do you know?

Elements & Compounds: Pure vs. Mixtures

CLASSIFYING MATTER FOLDABLE In the Elements booklet: -Pure substance made of all the same types of atoms -CANNOT be broken down into simpler substances -On the periodic table Example: Carbon

CLASSIFYING MATTER FOLDABLE In the Compounds booklet: -Combination of two or more elements (same or different) that are combined chemically -They CAN only be broken down by a chemical change (reaction) Example: Salt

CLASSIFYING MATTER FOLDABLE Mixture Combination of two or more pure substances that can be separated by physical means. Homogeneous -Composition is uniform throughout -Also called a solution Example: 30% alcohol + 70% water = solution Example: salt water, air, brass

CLASSIFYING MATTER FOLDABLE Mixture Combination of two or more pure substances that can be separated by physical means. Heterogeneous -Composition and properties are not uniform -Individual substances remain distinct Example: granite, vegetable soup, Italian dressing

 What is a physical property?  What are examples of physical properties we have explored so far?

PropertyWaterEthanol Appearance Odor Flammability Density Melting point Boiling point

 Represent the mixtures in both tubes at the particle level.  What is the difference between these 2 mixtures?

 How could we use these physical properties to separate a mixture?  When might we need to use this in real life outside the classroom?

SEPARATION TECHNIQUES