Lesson 7 Matter and how it changes
Matter makes up all the material found in the
universe. Matter has got two types of properties:
-
General
Properties: Mass (the
quantity of matter in an object, g, kg…) and volume (the amount of space
and object occupies cm3 or m3).
-
Specific
Properties: The qualities that
make it different from other types of matter such as elasticity or
density. Density is calculated in this way:
Mass
Density: -----------
Volume
There are two kind of substances:
-
Pure substances: They are made of one single substance
and can be solid, liquid or gas and can change from one state to another.
-
Mixtures: They are formed by two or more pure
substances, these substances are called components.
The mixtures can be heterogeneous (if
you can see the different components of the mixture) or homogeneous (also
known as solutions, you can´t identify the components of the mixture)
Changes of matter can be :
a) Physical: They can be:
-
Changes of state: solid, liquid or gas.
-
Expansion: Like gases or the liquid in a thermometer
-
Changes of
movement
-
Deformations
b) Chemical changes: The substances that the material is made of change
into a new substance that didn´t exist. It´s known as chemical reactions.
Combustion and oxidization are two kind of chemical changes. In living beings we find fermentation,
digestion and photosynthesis.
