The convention used for the chemical symbol of an element is so that you can determine the Atomic Mass.
The first letter is a capital letter.
With this symbol:
The molybdenum chemical symbol is Mo.
The correct chemical symbol of magnesium is Mg.
The chemical symbol for Helium is He.
The chemical symbol for strontium is Sr. The chemical symbol for copper is Cu.
With this symbol:
A chemical symbol is simply an abbreviated way of writing a particular chemical. The symbol is a much more convenient way of identifying each element. Some examples are "O" for oxygen and "H" for hydrogen.
To simple identify a chemical element, avoiding the writing of the whole name.
Each chemical element has a different chemical symbol formed from one or two letters: H for hydrogen, U for uranium, Cl for chlorine, Ar for argon, etc. Symbols are used for simplicity in writing equations, etc. The chemical symbol can be considered as a code.
The chemical symbol for indium is In
The chemical symbol of curium is Cm.
The molybdenum chemical symbol is Mo.
They're abbreviations to help make writing out chemical formulas easier.
The correct chemical symbol of magnesium is Mg.
Ce is the chemical symbol for cerium
The chemical symbol for iron is Fe and the chemical symbol for nickel is Ni.
Be is the chemical symbol for Beryllium.