Beryllium's chemical symbol is Be.
The chemical symbol for iron is Fe, and the chemical symbol for nickel is Ni.
The chemical symbol for tellurium is Te.
The symbol for tantalum is Ta.
The chemical symbol for phosphorus trichloride is PCl3.
"Carbogen" isn't a word in the dictionary. This is either a trade name for something or you have confused carbon and nitrogen.
The molybdenum chemical symbol is Mo.
Beryllium's chemical symbol is Be.
The chemical symbol for iron is Fe, and the chemical symbol for nickel is Ni.
The chemical symbol for chlorate is ClO3.
The chemical symbol for bromine is Br.
The chemical symbol of radon is Rn.
The chemical symbol for calcium is Ca.
The chemical symbol for radium is Ra.
Copper has Cu as its chemical symbol.
The chemical symbol for tellurium is Te.
The chemical symbol for silicon is Si.