Classification of Matter by Composition
Matter – anything that has mass and
takes up space
Mass – the amount of matter in the object
(grams, Kg)
Volume - the amount of space that
matter occupies (m3, mL)
Solid - matter that has a definite
shape and volume.
Particles are vibrating in place, but they cannot move
freely.
Liquid – matter that does not have a
definite shape but does have a definite volume; a liquid takes the shape of its
container.
Particles can move freely past each other, however,
they remain in a fixed volume.
A gas is
matter that does not have a definite shape or volume.
Gas particles can move freely and fill the spaces they
are in.
Pure substance – a substance made up of only one
type of matter; e.g., sugar, distilled water, copper wire are all pure
substances. Pure substances appear uniform or homogeneous;
this means that every part of the substance has the same composition as every
other part.
Mixture – a substance made up of two or more
different substances; e.g., pizza, soft drinks, eggs. Each substance inside the
mixture keeps its own properties; e.g., you can’t see the sugar in soft drinks,
but you can taste it.
Classifying
Mixtures – mixtures
can be grouped into 2 major categories; mechanical mixtures and solutions.
Mechanical
mixtures – the
different parts of the mixture can be seen; the mixture does not have the same
properties throughout.
Sometimes, it’s
easy to see the different types of matter throughout the mixture; e.g., snack
mix; sometimes you need a microscope.
These mixtures
are said to be heterogeneous, this means that it is made up of
different substances with different appearances and properties.
Solutions – these mixtures have the same
appearance throughout, but they are made up of two or more substances.
Solutions are made when you dissolve one substance into another.
All solutions are
said to be homogeneous mixtures because they look the same
throughout even though they are made up of different substances; e.g.,
dissolving sugar in tea.
