PURE SUBSTANCES VS. MIXTURES PENTONEY 2017
WHAT IS A PURE SUBSTANCE? Classification of matter that includes elements, molecules and compounds Cannot be separated by physical means such as distillation, filtration, or sifting.
SUBSTANCES Pure substance: 1. Element 2. Molecule 3. Compound Not one of those? NOT A PURE SUBSTANCE!
ELEMENT: CHEMISTRY: MIXTURES AND PURE SUBSTANCES One or more of the same type of atom. Ex: N N2 Both of these examples are called an element as we only have the element Nitrogen (N) and nothing else.
SUBSTANCES COMPOUND: Two or more atoms chemically combined, at least one is different. Ex: CO2 (Carbon Dioxide) NaCl (salt) Both of these examples are types of compounds.
SUBSTANCES MOLECULE: 2 or more atoms chemically combined. Ex: N2 N3 H2O
SUBSTANCES Ex: N2 N3 (These molecules are more specifically called an Element because they are made up of only one type of atom.)
*CHEMISTRY: MIXTURES AND PURE SUBSTANCES Ex: H2O (This is also a molecule, as it has 2 or more atoms combined. But its more specific name is a compound. )
SUBSTANCES The words ELEMENT and COMPOUND are specific types of molecules.
ALL OF THE BOXES BELOW SHOW AN EXAMPLE OF A PURE SUBSTANCE ELEMENT (C) ELEMENT (O2) COMPOUND (CO2)
SUBSTANCES Examples of pure substances: Salt (NaCl) Sugar C6H12O6 (Glucose = Sugar) H2O (Water) ELEMENTS (like gold, silver, oxygen, nitrogen any on the periodic table)
SUBSTANCE MIXTURE: two or more pure substances thrown together. All substances keep their own identities. *Example: When I mix sugar and water, I get the mixture sugar-water. The sugar still has its own identity (it is sweet), the water still has its own identity (its still water). Nothing new is created, and both can be separated physically (boiling).
SUBSTANCE There are two types of mixtures: 1. Homogenous 2. Heterogeneous
SUBSTANCE Homogenous Mixture: Evenly mixed mixture Examples: Milk Air (a mixture of gases you breath in) Soda Juice
WHAT IS A HOMOGENOUS MIXTURE? A mixture that is evenly distributed Commonly called solutions. Solution = Solute + Solvent Solute: stuff being dissolved Solvent: stuff doing the dissolving The solvent is present in greater quantity The solute is present in the lesser quantity Ex: Salt water: Salt = solute, Water = solvent
SUBSTANCE Heterogeneous Mixture: Unevenly mixed mixture. Example: Salad Legos Cookie dough ice-cream Chicken noodle soup
SUBSTANCE ALL MIXTURES ARE PHYSICALLY COMBINED AND CAN BE PHYSICALLY SEPARATED.
SUBSTANCE Ways to physically separate a mixture: Boiling: evaporates liquid Sifting: Picking out pieces (like in cookies dough ice-cream =) ) Filtering: Just like a pool filter, it takes out unwanted things.
*CHEMISTRY: MIXTURES AND PURE SUBSTANCE What is the biggest differences between a mixture and a pure substance? (COPY CHART) Mixtures Are physically mixed together Can be physically separated Pure substance Chemically combined (bonded) Must be chemically separated
CLASSIFYING MATTER (COPY CHART) Matter Pure Substances Mixtures Homogeneous Heterogeneous Elements Molecules Compounds milk, tea Rocky Road ice cream, muddy water Fe, O Fe2 H 2 O, CO 2
SUBSTANCE REVIEW Question 1: Which substance is not a compound? a. Ne c. SiO2 b. HCN d. H2O2
SUBSTANCE REVIEW Question 1: Which substance is not a compound? a. Ne c. SiO2 b. HCN d. H2O2
SUBSTANCE REVIEW Question 2: The components of a homogeneous mixture could be described as a. inseparable c. chemically bonded b. evenly mixed d. unevenly mixed
SUBSTANCE REVIEW Question 2: The components of a homogeneous mixture could be described as a. inseparable c. chemically bonded b. evenly mixed d. unevenly mixed
SUBSTANCE REVIEW Question 3: Iron filings are thrown into a pile of sand. What is the best way to separate this mixture? A. Use a magnet to pick up the sand. B. Sift through the sand for all of the iron. C. Use a magnet to pick up the iron filings.
SUBSTANCE REVIEW Question 3: Iron filings are thrown into a pile of sand. What is the best way to separate this mixture? A. Use a magnet to pick up the sand. B. Sift through the sand for all of the iron. C. Use a magnet to pick up the iron filings.
SUBSTANCE REVIEW Question 4: A substance contains two components joined by physical means. Which best describes the substance? A. element B. compound C. mixture D. molecule
SUBSTANCE REVIEW Question 4: A substance contains two components joined by physical means. Which best describes the substance? A. element B. compound C. mixture D. molecule
SUBSTANCE REVIEW Question 5: Which best describes water? A. a compound B. an element C. a heterogeneous mixture D. a homogeneous mixture
SUBSTANCE REVIEW Question 5: Which best describes water? A. a compound B. an element C. a heterogeneous mixture D. a homogeneous mixture
SUBSTANCE REVIEW Question 6: Which image below is a mixture? A B C D
SUBSTANCE REVIEW Question 6: Which image below is a mixture? A B C D Element Compound molecule mixture of elements + compounds