2.1 Properties of Matter
Example of properties of matter are
- is a solid shiny or dull? - does a liquid flow quickly or slowly? - is a gas odorless or does it have a smell?
Physical change
Some properties of a material change, but the composition of the material does not change. Words such as boil, freeze, melt, condense, break, split, grind, cut, and crush are used to describe physical changes.
Every sample of a given substance has identical intensive properties because every sample has the same composition.
Every sample of a given substance has identical intensive properties because every sample has the same composition.
Name two categories used to classify properties of matter.
Extensive and intensive
Properties used to describe matter can be described as...
Extensive or intensive properties
Solid
A form of matter that has a definite shape and volume. -shape doesn't depend on shape of container -particles are packed tightly together, often in an orderly arrangement -as a result, they are almost incompressible (difficult to squeeze into a smaller volume) -expand only slightly when heated
Liquid
A form of matter that has an indefinite shape, flows, yet has a fixed volume. They are almost incompressible, but they tend to expand slightly when heated.
Gas
A form of matter that takes both the shape and volume of its container. A gas can expand to fill any volume. They are also easily compressed into a smaller volume.
Mass
A measure of the amount of matter the object contains
Volume
A measure of the space occupied by the object
Intensive property
A property that depends on the type of matter in a sample, not the amount of matter...an example is absorbency (leather or rubber basketballs)
Physical property
A quality or condition of a substance that can be observed or measured without changing the substance composition...examples are hardness, color, conductivity, and malleability
Matter
Anything that has mass and takes up space
How would understanding the properties of matter be helpful in other fields of study besides chemistry?
As a chef you may your food may be too hard, so you need to add more liquid.
Explain why all samples of a given substance have the same intensive properties.
Because every sample has the same composition
Which property in Table 2.1 can most easily distinguish sodium chloride from the other solids?
Color
Extensive property
Depends on the amount of matter in a sample...mass and volume are both examples
Vapor
Describes the gaseous state of a substance that is generally a liquid or solid at room temperature, as in water vapor.
Substance
Matter that has a uniform and definite composition...examples are aluminum and copper (pure substances)
Understanding matter begins with________.
Observation
Describe the two categories used to describe physical changes.
Reversible (such as melting and freezing) and irreversible (such as breaking and splitting)
Is the freezing of mercury a reversible or irreversible physical change? Explain your answer.
Reversible because you can leave the Mercury in room temperature and let it go back to a liquid.
What can physical changes be classified as?
Reversible or irreversible
What are the three states of matter?
Solid, liquid, and gas...examples are ice, water, and steam
Name three states of matter.
Solid, liquid, gas
In what way are liquids and solids different?
Solids have a definite shape while liquids have an indefinite shape. The particles in a liquid are free to flow past one another while the particles in a liquid are packed closely together in a rigid arrangement.
The word vapor and gas are sometimes used interchangeably. What's the difference?
The term gas is used for substances, like oxygen, that exist in the gaseous state at room temperature. Vapor describes the gaseous state of a substance that is generally a liquid or solid at room temperature, as in water vapor!
In what way are liquids and gases alike?
They both have indefinite shape and particles are move freely.
Explain why samples of platinum and copper have the same extensive properties but not the same intensive properties.
They have the same extensive properties because the sample contains the same amount of matter. They do not have the same intensive properties because they do not have the same composition or type of matter.
