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Dismissal Procedures. When the bell rings you are to be in your seat You are to stayed seated until dismissed No one will be dismissed unless: Everyone is seated All notebooks, clickers and calculators are returned to their proper place Lab is clean and tidy.
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Dismissal Procedures • When the bell rings you are to be in your seat • You are to stayed seated until dismissed • No one will be dismissed unless: • Everyone is seated • All notebooks, clickers and calculators are returned to their proper place • Lab is clean and tidy
Introduction: Matter & Measurement Klein Forest Chemistry
Chemistry What is chemistry? It is the study of the composition of matter and the changes that matter undergoes. What is matter? It is anything that takes up spaceand has mass.
Elements, Compounds & Mixtures A substance is matter that has a definite composition and constant properties It can be an element or a compound
Elements, Compounds & Mixtures An element is the simplest form of matter. It cannot be broken down further by chemical reactions
Elements, Compounds & Mixtures A compound can be separated into simpler forms It is a combination of two or more elements
Mixtures A mixture is a physical blend of two or more substances 1. Heterogeneous Mixtures Not uniform in composition Properties indefinite & vary Can be separated by physical methods
Mixtures 2. Homogeneous Mixtures Completely uniform in composition Properties constant for a given sample Cannot be separated by physical methods (need distillation, chromatography, etc) Sometimes called solutions
Physical & Chemical Properties Physical property – characteristics of a pure substance that we can observe without changing the substance; the chemical composition of the substance does not change
Physical & Chemical Properties Chemical property –describes the chemical reaction of a pure substance with another substance; chemical reaction is involved
Physical & Chemical Properties Physical properties appearance odor melting point boiling point hardness density solubility conductivity Chemical properties reaction with oxygen (flammability) rxn with water rxn with acid Etc….
Intensive & Extensive Properties Intensive properties Do not depend on the amount of sample being examined temperature odor melting point boiling point hardness density Extensive properties Depend on the quantity of the sample mass volume Etc….
Physical & Chemical Changes Physical changes The composition of the substance doesn’t change Phase changes (like liquid to gas) Evaporation, freezing, condensing, subliming, etc. Tearing or cutting the substance Chemical changes The substance is transformed into a chemically different substance All chemical reactions
Signs of a Chemical Changes permanent color change gas produced (odor or bubbles) precipitate (solid) produced light given off heat released (exothermic) or absorbed (endothermic)
Chemical, Physical, Property, Change? • Color ?
Chemical, Physical, Property, Change? • Color ? • Ice melting?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Reacts with acid?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Reacts with acid? • Density?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Evaporating alcohol? • Reacts with acid? • Density?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Evaporating alcohol? • Reacts with acid? • Density? • Paper burning?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Evaporating alcohol? • Electrolysis of water? • Reacts with acid? • Density? • Paper burning?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Evaporating alcohol? • Electrolysis of water? • Reacts with acid? • Density? • Paper burning? • Temperature?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Evaporating alcohol? • Electrolysis of water? • Length? • Reacts with acid? • Density? • Paper burning? • Temperature?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Evaporating alcohol? • Electrolysis of water? • Length? • Reacts with acid? • Density? • Paper burning? • Temperature? • Thermal conductivity?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Evaporating alcohol? • Electrolysis of water? • Length? • Vinegar+baking soda foaming? • Reacts with acid? • Density? • Paper burning? • Temperature? • Thermal conductivity?
Chemical, Physical, Property, Change? • Color ? • Ice melting? • Evaporating alcohol? • Electrolysis of water? • Length? • Vinegar+baking soda foaming? • Reacts with acid? • Density? • Paper burning? • Temperature? • Thermal conductivity? • Water boiling?
Chemical, Physical, Property, Change? • Cutting your fingernails ?
Chemical, Physical, Property, Change? • Cutting your fingernails ? • Decomposes when heated?
Chemical, Physical, Property, Change? • Cutting your fingernails ? • Solubility in water? • Decomposes when heated?
Chemical, Physical, Property, Change? • Cutting your fingernails ? • Solubility in water? • Decomposes when heated? • Discolors in air (like apples)?
Chemical, Physical, Property, Change? • Cutting your fingernails ? • Solubility in water? • Brittleness? • Decomposes when heated? • Discolors in air (like apples)?
Chemical, Physical, Property, Change? • Cutting your fingernails ? • Solubility in water? • Brittleness? • Decomposes when heated? • Discolors in air (like apples)? • Weight?
Chemical, Physical, Property, Change? • Cutting your fingernails ? • Solubility in water? • Brittleness? • Malleability? • Decomposes when heated? • Discolors in air (like apples)? • Weight?
Chemical, Physical, Property, Change? • Cutting your fingernails ? • Solubility in water? • Brittleness? • Malleability? • Decomposes when heated? • Discolors in air (like apples)? • Weight? • Changes litmus blue (or red)?
Chemical, Physical, Property, Change? • Decomposes when heated? • Discolors in air (like apples)? • Weight? • Changes litmus blue (or red)? • Cutting your fingernails ? • Solubility in water? • Brittleness? • Malleability? • Solubility in oil?
Chemical, Physical, Property, Change? • Decomposes when heated? • Discolors in air (like apples)? • Weight? • Changes litmus blue (or red)? • Soda foaming when shaken? • Cutting your fingernails ? • Solubility in water? • Brittleness? • Malleability? • Solubility in oil?
Chemical, Physical, Property, Change? • Decomposes when heated? • Discolors in air (like apples)? • Weight? • Changes litmus blue (or red)? • Soda foaming when shaken? • Cutting your fingernails ? • Solubility in water? • Brittleness? • Malleability? • Solubility in oil? • Electrical conductivity?