6.1.2 Symbols for the
Elements
Suppose a Canadian chemical company
hopes to sell its products in china and
they need to hire an interpreter to
communicate with potential customers.
But, the interpreter doesn’t need to
translate the names of any chemicals.
Why?
All countries use the same chemical
symbols to represent elements and
compounds.
SOME MODERN SYMBOLS FOR ELEMENTS
Calcium Ca
Chlorine Cl
Oxygen O
Tin
Sn
Lead
Pb
Mercury Hg
The name of the element sometimes
depended on……..
Polonium……after the country Poland
Einsteinium…..after Albert Einstein
Uranium……..after the planet Uranus
Due to time and the difficult nature in
writing out these names, a system of
element symbols was developed.
Chemical Formulas
Just as single symbols are used to represent
elements, combinations of these symbols are
used to represent compounds.
A chemical formula is the combination of
symbols that represents a particular
compound.
The chemical formula indicates which elements
are in the compound and in what proportion
they are present.
E.g.,
H2O, CH4, H2O2, NaCl, and NaNO3.
Each symbol of a formula represents an atom of
an element.
E.g.,
H2O
Subscripts tell how many atoms
there are in a molecule.
1 molecule of water
2 Atoms of hydrogen
1 Atom of oxygen
The formula for water tells you that the
elements are present in the ratio ( law of
definite proportions) of two atoms of hydrogen
to one atom of oxygen.