3Are the following considered matter? Key TermsChemistry: explains the structure and properties of matterMatter: anything that occupies space and has massMass: amount of matter an object containsAre the following considered matter?Car, pencil, heat, thoughts/ideas, light, air, radio waves, water, cell
4States of Matter Most common states of matter: Solid: particles in fixed position, tightly packed; definite shape and volume.Liquid: particles tightly packed but can slide past each other; fixed volume but changing shape.Gas: particles in constant state of motion and rarely stick together; shape and volume change.
6Pure SubstancesPure substance: matter with a uniform and definite composition; contains 1 kind of matterCannot be separated physicallyEx: gold (Au), sugar/sucrose (C12H22O11), water (H2O), carbon dioxide (CO2)
7Types of Pure Substances Compound2 or more elements combinedCan be broken down into simpler substances chemicallyEx: salt (NaCl), baking soda (NaHCO3), sugar(C6H12O6), caffeine, water (H2O)ElementSimplest form of matterCannot be broken down any further by chemical or physical means!!Represented on periodic table of elementsEx: oxygen (O2), pure gold (Au), iron (Fe)
8Symbols and FormulasChemical Symbol: each element is represented by one- or two- letter’s.First letter is always capitalized.
9Chemical Formula: shows which elements are in a compound and how many of each. Numbers in subscript show the # of atoms of each elementEx: sugar C6H12O6water H2Ocarbon dioxide CO26 carbon atoms,12 hydrogen atoms, and6 oxygen atoms
11Mixture Mixture Made up of 2 more substances Can be physically separatedEx: salt water, lemonade, chocolate milk, dinner salad, blood
12Classifying Mixtures Homogenous: Heterogeneous: Same throughout, completely dissolvedCalled a solutionEx: Sugar water, air, steel, tableware (sterling silver), salt waterHeterogeneous:Different compositions within the mixtureEx: orange juice, granite rock, blood
13Separating Mixtures Mixtures are separated through physical means. Magnetism to separate metal filamentsFiltration to separate solid from liquidDistillation = liquid is boiled separating vapor from liquid or solid substance
16Physical PropertyPhysical Property: quality or condition of a substance that can be observed or measured without changing the substance’s compositionIncludes color, solubility, odor, hardness, density, melting point, boiling pointEx: water is clear, has no odor, density is 1g/ml, boils at 100°C
17Physical ChangesPhysical Change: is a change of matter from one form to another without changing its identity.Includes dissolving (mixing), crushing, melting, freezing, evaporating, bending, cuttingIt is reversible!!!Ex: Breaking a piece of chalk into two, getting your hair cut, melting ice, crushing aluminum can, mixing oil and vinegar
19Chemical ChangesChemical reactions occur when substances undergo chemical changes to form new substancesThey are irreversible!Signs of a chemical change:Gas produced (bubbling)Odor produced (gas)Color changeRustingBurningPrecipitate (solid) formedReactivity (one chemical reacts with another)Energy (light, heat, cold) released or produced
20Chemical Equation 4H2 + O2 2H2O means “yields” Reactants = substance starting a reaction, on left side of arrowA + B CIron + sulfur iron sulfideProducts = substance formed in a reaction, on the right side of the arrow
21Conservation of MassLaw of Conservation of Mass = matter is neither created nor destroyed…Thus, mass of reactants = mass of productsAtoms in a chemical reaction don’t change, they rearrange!The same number of each kind of atom must be on the left side as well as the right!Ex: H2CO3(aq) H2O(l) + CO2(g)H = 2, C =1, O = 3H = 2, C =1, O =3