physical and chemical properties. physical properties a physical property of a substance is any...
TRANSCRIPT
Physical and Chemical Properties
Physical Properties
•A physical property of a substance is any
property of a substance that you can
observe without changing it’s identity.
Physical Properties: Appearance•Physical properties include how the
substance looks•These properties include color, shape,
size, state of matter (solid, liquid, gas)
Physical Properties: Behavior
•Physical properties also include how a substance behaves
•These properties include magnetism, elasticity, ductility, malleability, ability to flow
•Malleability is the material’s ability to be compressed•Ductility is a material’s ability to be stretched
Physical Properties: Touch & Smell
•Touch and smell are also physical properties of a substance.
Physical Properties: Density•Density is the mass of an object divided
by its volume•D=m/v=g/ml•The density of water is 1 g/ml
mD v
m=DvD=m/vV=m/D
Physical Change•A change is size, shape, or state of matter
is a physical change.•The identity of the substance remains the
same with a physical change.
Using Physical Properties to Separate•Mixtures can also be separated by
physical properties.•Distillation is the process of using heat to
remove liquid from a mixture and then• recompensing it.
Chemical Properties•A chemical property is a characteristic of
a substance that indicates whether it can undergo a chemical change. These include reactivity, flammability, stability, and toxicity
•Reactivity is the ability of a substance to react with another
•Flammability is the ability of something to burn
•Stability is a substances tendency not to react
•Toxicity is the degree to which a substance can damage a living or non-living organisms
Chemical Change
•During a chemical change, the identity of the substance changes.
•New substances are formed during a chemical change.
•Some indicators of a chemical change is a change physical properties•Chemical changes can’t be undone by physical changes
Using Chemical Change to Separate•Chemical changes can be used to
separate things or return them to their original state.
•An example would be tarnish on silver. This can be turned back into silver through a chemical reaction with aluminum foil, baking soda, and water.
Comparing Chemical & Physical Properties
Substance Physical property Chemical property
Helium less dense than air nonflammable
Wood grainy texture flammable
Baking soda white powderreacts with vinegar to produce bubbles
Iron malleable reacts with oxygenPowdered sugar white powder does not react with vinegarRubbing alcohol clear liquid flammable
Red food coloring red colorreacts with bleach and loses color
Conservation of Mass•The law of
conservation of mass states that the mass of all of the substances present before a chemical change is equal to the mass of all substances that remain after.
•Mass of products = mass of reactants