The entry for every element
contains a symbol and two numbers.
Symbol:
One- or two-letter representation for an element.
For instance, the symbol for
element hydrogen is the letter H.
Oxygen, O, and sodium, Na, not
S.
S is the symbol for Sulfur.
Symbol for nitrogen is N, but for
potassium its K, not P.
P is the symbol for
Phosphorus.
The two numbers are atomic number
and relative atomic mass.
Atomic number represents
the number of protons in the
nucleus.
Relative atomic mass
representative how heavy the atom is relative to the
mass of hydrogen atom.