Chap 2 chem & phy propertiesPresentation Transcript
Physical Properties• Property is the ability to do something• Can be observed or measured without changing the matter’s identity• Used to identify substances by physical characteristics
Examples of physical properties and physical changes• Physical Property • Physical Change• Boiling Point • Boiling• Freezing Point • Freezing• Melting Point • Melting• Condensation Point • Condensing• Evaporation Point • Evaporating• Ductile • Stretching into wire• Malleable • Hammer into sheet• Solubility • Dissolving• electric conductivity • Moving electricity
Continued• Physical Property • Physical Change• Flexibility • Bending• State at room temp • Change of state• Brittle • Shattering• Magnetism • Magnetic conduction• Thermal conductivity • Moves thermal energy• Color• Odor• Shiny• Dull• Hardness• density
NOT physical properties• Never use weight, mass, volume, shape or size to describe matter
• Densities of substances is unique to the substance• Determines if a substance will sink or float• H2O has density of 1, any substance with a density greater than 1 will sink, less than 1 will float• Liquid substances will create layers depending on densities
Physical Change• Actually making the change• A change in matter from one form to another without a change in chemical properties• In other words, physical changes do not change the identity of the matter
Chemical Properties• Chemical property – a property of matter that describes a substances ability to participate in chemical reactions• Examples of chemical properties – Flammability – ability to burn – Reactivity with acid – Reactivity with water – Reactivity with oxygen – Reactivity with other elements
• Reactivity is the ability of two or more substances to chemical combine and form one or more new substances• Characteristic properties-properties that remain the same no matter the size of the matter• Characteristic properties can be both physical, such as solubility and density and chemical such as flammability and reactivity
• Chemical change-when one or more substances change into entirely new substances with different properties• Chemical changes are the process by which substances actually change into new substances• Chemical properties describe which chemical changes will occur.
Chemical Changes• Signs that indicate a chemical change:• color change,• odor change,• production of thermal energy (heat),• production of cold,• fizzing,• foaming,• bubbling• Sound produced,• light being given off• Precipitate formed (solid)• Oxidation (rust, tarnishing)
• Chemical changes change the identity of the matter therefore is very difficult to undo• Composition-type of matter and the way the matter is arranged• To determine if a physical or chemical change has happened, ask yourself, did the composition of the matter change• EX: H2O is 2 hydrogen atoms and 1 oxygen atom whether it is a solid, liquid or a gas.
Difference between physical and chemical propertiesPhysical ChemicalCan be observed Not easily observed and without changing the changes the identity of the substances into substance something newNo reaction takes place A reaction takes place