Conservation of Mass ✴ During any chemical reaction, the mass of the products is always equal to the mass of the reactants

Classification of Matter ALL matter can be classified as either a pure substance or a mixture

Mixtures ✴ A mixture is a blend of two or more types of matter, each of which retains its own identity and properties ✴ Chicken noodle soup ✴ Air ✴ Salad dressing ✴ Lucky charms

Mixtures can be separated physically: ✴ Filtration ✴ Used to separate a solid(s) from a liquid ✴ Decanting (“pour off”) ✴ Oil/vinegar ✴ Paper chromatography ✴ Centrifugation

Classifying Mixtures ✴ Based on the distribution of their components, mixtures can be classified as: ✴ Heterogenous ✴ Homogenous

✴ Homogenous mixture (solution) ✴ Composition is uniform throughout the mixture ✴ Air, salt water, orange juice (no pulp), stainless steel (Fe,Cr, and Ni) ✴ Heterogenous mixture ✴ Composition is not uniform throughout the mixture ✴ Chicken noodle soup, Italian salad dressing

✴ A homogeneous mixture can sometimes look the same ✴ They appear the same until light is passed through ✴ In a colloid, the light is scattered–Tyndall Effect ✴ Examples: Milk, orange juice (no pulp), pudding Colloid

✴ Elements ✴ The simplest form of matter that has a unique set of properties ✴ There are more than 100 known elements (Fe, N, He, etc.) ✴ Compounds ✴ A substance that contains two or more elements in chemically combined in a fixed proportion ✴ H 2 O (2 atoms of hydrogen for every one atom of oxygen) Pure Substances

Difference between Elements & Compounds ✴ Compounds can be broken down into simpler substances by chemical means, but elements cannot ✴ Water can be broken down into its elements (hydrogen and oxygen) through electrolysis

Determine whether the following is an element, compound, homogeneous mixture, or heterogeneous mixture Copper Salt (Sodium Chloride) Silicon Sugar dissolved in water Concrete Sugar (sucrose) Salad Dressing Air Stainless Steel Egg Orange Juice (with pulp) Calcium Chloride Orange Juice (no pulp)

ELEMENTS AND COMPOUNDS

Representing Elements and Compounds ✴ Elements ✴ Chemical symbols ✴ First letter is always capitalized while the second letter (if used) is always lowercase ✴ Compounds ✴ Chemical formulas

Symbols and Latin Names for Some Elements NameSymbolLatin name SodiumNanatrium PotassiumKkalium AntimonySbstibium CopperCucuprum GoldAuaurum SilverAgargentum IronFeferrum LeadPbplumbum TinSnstannum ✴ The element symbols that are used today are based on the Latin names of each of the elements

Compounds ✴ Subscripts in the chemical formula tell you how many of each type of element are in the compound ✴ H 2 O (2 atoms of hydrogen for every one atom of oxygen) ✴ CO 2 ✴ NO