They are the short hand representation for each of the elements.
No, the symbol "H" stands for Hydrogen on the periodic table. The symbol "He" stands for Helium on the periodic table.
As is the symbol of arsenic
No element has the symbol A
there is no element with the symbol A.
it is the symbol for astatine.
Iodine
Helium.
Sulfur is represented by the symbol S on the periodic table.
Manganese
manganese
Germanium
Be is the chemical symbol for beryllium.