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2.1 Classifying Matter. Objectives. Measure length, mass, volume, temperature, and time during an investigation. Compare the densities of regular and irregular objects using their respective measures of volume and mass.
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Objectives • Measure length, mass, volume, temperature, and time during an investigation. • Compare the densities of regular and irregular objects using their respective measures of volume and mass. • Identify pure substances by their physical and chemical properties (color, luster, reflectivity, hardness, conductivity, density, pH, etc.). • Distinguish between physical and chemical changes in matter. • Classify a substance as being made of one kind of atom (element) or a compound when given the molecular formula or structural formula for the substance. • Compare and contrast the common properties of metals, nonmetals, and metalloids. • Compare and contrast the properties of acidic, basic, and neutral solutions.
Why??? • Why do things act the way they do???
What I Want to Know Is??? • More Scientific Example: +
Pure Substances • A pure substance is matter that contains only one kind of particle. • Every sample of a pure substance has the same properties because a pure substance has a fixed, uniform composition. • Pure substances are either elements or compounds. Salt (NaCl) Gold Water (H2O)
Objectives • Measure length, mass, volume, temperature, and time during an investigation. • Compare the densities of regular and irregular objects using their respective measures of volume and mass. • Identify pure substances by their physical and chemical properties (color, luster, reflectivity, hardness, conductivity, density, pH, etc.). • Distinguish between physical and chemical changes in matter. • Classify a substance as being made of one kind of atom (element) or a compound when given the molecular formula or structural formula for the substance. • Compare and contrast the common properties of metals, nonmetals, and metalloids. • Compare and contrast the properties of acidic, basic, and neutral solutions.
Elements • An element is a substance that can not be broken down into simpler substances. • The smallest particle of an element is an atom. • An element has a fixed composition because it contains only one type of atom. H atoms Na atom Cl atoms
Question #1 All elements and compounds are classified as _____. • Mixtures • Pure substances • Massive material. • Deadly.
Question #2 The smallest particles of all elements are _____. • Molecules • Ions • Atoms • Protons
Symbols • Scientists use symbols to represent the names of the elements. • Each symbol has one or two letters from the elements name. • The first letter is always capitalized, the second letter is not. Hydrogen - HOxygen - OSodium - Na ?
Compounds • A compound is a substance made up of two or more elements that are chemically bonded together. • The properties of a compound differ from the elements that make it up. • The ratio of the elements in a compound are always the same. Carbon Dioxide (CO2) Water (H2O)
Talk to Shoulder Partner • There are two types of pure substances. What are they? Elements Compounds
Closure & Summary Question Be sure to write a COMPLETE SENTENCE!!! What is the difference between an element and a compound???
Homework • Density Practice Problems! • Given to you Monday! • Candy Density lab is due MONDAY!
Objectives • Measure length, mass, volume, temperature, and time during an investigation. • Compare the densities of regular and irregular objects using their respective measures of volume and mass. • Identify pure substances by their physical and chemical properties (color, luster, reflectivity, hardness, conductivity, density, pH, etc.). • Distinguish between physical and chemical changes in matter. • Classify a substance as being made of one kind of atom (element) or a compound when given the molecular formula or structural formula for the substance. • Compare and contrast the common properties of metals, nonmetals, and metalloids. • Compare and contrast the properties of acidic, basic, and neutral solutions.
Let’s Get Our Brains Going • Talk Fast!!! • With shoulder/table partner. • The tallest person will start as guesser. • The shortest person will start as talker. • When you complete, put two claps and a hand in air.
Round 1 Element Density Meters
Round 2 Pure Substance Compound Graduated Cylinder
Throw the Ball When you answer your questions you must TELL WHAT NOTE YOU FOUND IT IN. • What is a pure substance? • What two types of materials are pure substances? • What is the difference between an element and a compound? • What is the smallest particle of an element called? • (Not in notes but just think about this) If a material is not a pure substance, what would it be called?
Mixtures • A mixture is a physical combination of two or more pure substances. • The substances are combined without chemical bonding. • The substances in a mixture keep their original properties. Salt + water = Salt water
Types of Mixtures • Heterogeneous mixtures – individual components can be easily recognized. • Looks different in different parts • salad pizza • granite
Types of Mixtures • Homogeneous mixtures – individual components can not be easily recognized. • Looks the same throughout • Also known as solutions • 14 kt gold pop chemical solutions
Talk to Shoulder Partner What is the difference between heterogeneous mixtures and homogeneous mixtures?
Suspension • A suspension is a heterogeneous mixture in which one part settles out over time. • It has to be stirred or agitated to keep the particles suspended. • The particles are large enough to scatter light. • orange juice • chocolate milk • Italian dressing
Colloids • A colloid is a special type of suspension in which the suspended particles do not settle out. • The suspended particles are large enough to scatter light. whipped cream Milk fog
Table Conversation • What is the difference between a suspension and a colloid?
Example of Colloid DEMO
Summary Remember to write in complete sentences!!! • What is the difference between a heterogeneous mixture and a homogeneous mixture?
Closure • Density of Candy Labs is DUE RIGHT NOW!!!
Review – Throw the Ball Use your table we created yesterday!!! • What is a pure substance? • What is an element? • How do we know what’s an element (if we can’t see atoms)? • What is a compound? • How can we tell the difference between heterogeneous and homogeneous mixtures?
Matter Pure substance Mixture Elements Compounds Heterogeneous Homogeneous • ______ • ______ • ______ • _______ • _______ • _______ suspension colloid solution • _______ • _______ • _______ • _______ • _______ • _______ • _______ • _______ • _______