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Classification of Matter. Review. physical change : the chemical composition (makeup or parts) of the matter stays the same . Ex: state changes (solid to liquid to gas), changing shape (ripping, squishing ). Review.
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Review • physicalchange: the chemical composition (makeup or parts) of the matter stays the same. • Ex: state changes (solid to liquid to gas), changing shape (ripping, squishing)
Review • chemicalchange: a compound’s chemical composition (makeup) is changed – it becomes a new substance • ex: burning, rusting, reacting
MATTER Mixture Pure Substance Homogeneous Mixture Heterogeneous Mixture Compound Element Atom Physically separated Chemically separated Can’t be separated
matter: has volume (takes up space), and mass • can be solid, liquid or gas • mixture: several different substances NOT chemically combined, can be physically separated into pure substances • homogeneous: evenly mixed (solution) • ex: salt water, air • heterogeneous: not evenly mixed • ex: sand, soup
pure substance: constant (same) composition (homogeneous), • ex: water H2O or lead Pb • compound or an element • compound: chemically bonded elements ex: CO2
element: can not be separated physically or chemically, made of a single kind of atom • atom: smallest particles of an element, can not be chemically separated
MOLECULES ELEMENT COMPOUND MIXTURE
Monatomic Diatomic ex: noble gases: He, NE, Ar, Kr… Ex: halogens: F2, Cl2, Br2, H2
What classification of matter? (from the flow chart) • Matter that can be physically separated and is uniform (evenly mixed). • Matter that can not be physically separated. • Matter that can not be physically separated and can not be decomposed (broken apart) by chemical means. • Matter that can be physically separated. • Matter that can be physically separated but does not have a uniform (evenly mixed) composition.
Matter that can not be physically separated but can be decomposed (broken down) by chemical means. • Can an element be broken down chemically? • How is a mixture different from a pure substance? • How is an element different from a compound?
Element or compound? • neon • sodium bichlorate • silver • potassium chloride • carbon dioxide • helium
An unknown silvery powder has a constant melting point and does not chemically or physically separate into other substances. The unknown substance can be classified as – A. an element B. a compound C. a mixture D. an alloy (a homogenous mixture of metals)
A student examines a sample of matter and finds that she can’t separate it into its parts physically or chemically. This matter is: a. an element b. a homogeneous mixture c. a heterogeneous mixture d. a gas
One example of a pure substance is: a. paper b. cookie dough c. rocks and sand d. water
Separating a mixture Is separating a mixture a chemical process or a physical process?
solvent: the part of a solution doing the dissolving (the liquid) • solute: a substance being dissolved in a liquid • solution: the mixture of a solvent and a solute SOLUTE SOLUTION SOLUTION SOLVENT
soluble: dissolves in a solvent • insoluble: does not dissolve
Salt and water? • filtration: insoluble solute not dissolved in a solvent • Ex: sand and water
evaporation: solute can not evaporate, but solvent can • ex: water and sand; water and salt
distillation: separation of a mixture of liquids that evaporate at different temperatures, by evaporating, condensing and collecting each liquid.
chromatography: Mixture of solids of different masses floating in a liquid. • Lighter solids move farther and faster! • Ex: ink, DNA
Experiment • What color is black ink? • Is ink a mixture or pure substance? • How could we find out?
What method would you use… • to separate sand from water? • to separate two kinds of paint mixed with one another? • to separate gasoline from water? • to separate salt from water?
With your group • Write the following words and phrases, one per index card, neatly! • matter • compound • element • homogeneous mixture • heterogeneous mixture • chromatography • solid • liquid • gas • temperature • kinetic theory • evaporation • condensation • filtration • melting • freezing • sublimation • deposition • solvent • solute • solution • distillation
Experiment • What color is black ink? • Is ink a mixture or pure substance? • How could we find out?
In your group • Mix up the cards and stack them face down. • Choose one person to draw first. That person picks up the top card. • They draw on the whiteboard until a group member guesses the word or phrase on their card. No letters or words may be drawn! • The correct guesser earns one point. • Then, group member 2 chooses a card and draws. • Continue taking turns.
Homework • Week 5 Homework p. 1-3