After this lesson, you should be able to...
- Explain the difference between an atom and a molecule.
- Identify a chemical formula given a molecular representation.
Most elements don't actually exist in nature as individual atoms. Atoms
readily combine (bond) to form molecules or networks. Some molecules and
networks are pure elements (i.e.
0_2
,
S_8
, graphite). Other molecules contain mixtures of elements and these are known
as compounds (i.e.
NaCl
,
H_2O
,
NH_3
,
C_6H_{12}O_6
). We will discuss the details of molecular and ionic compounds in later
lessons. For now, we are just going to introduce the various ways that
compounds can be represented.