2. Atoms
➲ The simplest particles that make up matter
➲ Represented by balls
3. Molecules
➲ Molecules are made when two atoms are
attracted to each other with strong forces
and bond
➲ When two or more atoms join together to
make a molecule, it is called a chemical
reaction
4. Elements
➲ Elements are substances formed by atoms
of a single type
Elements cannot be broken down into more
simple substances
➲ There are three kinds of elements:
Atomic elements
Molecular elements
Elements with a crystal structure
5.
6.
7. Compounds
➲ Compounds are substances formed by
different atoms, always combined in fixed
proportions
They are represented by formulas formed by the
symbols of their elements and subscript
numbers which indicate the number of atoms of
that element in the compound
CO2
➲ Two types of compounds
Molecular compounds
Compounds with a crystal structure
8. 1)Pure substances
Formed by similar particles
2)Mixtures
➲ Homogeneous mixture/solution: when we
cannot differentiate between their
components
Sea water, air
➲ Heterogeneous mixture: when we can
distinguish the components of the mixture
Granite rock
9. Substances and Mixtures
➲ Pure substances are formed by similar particles
(atoms or molecules)
Most of the matter that we see is a mixture of
substances
➲ The main difference between pure substances
and mixtures is that the first have well definied
specific propertires: density, fusion and boiling
temperatures, while mixtures do not
