one element or substance.
I is the chemical symbol for iodine.
I is the chemical symbol for iodine.
I is the chemical symbol for iodine.
Hydrogen
There's no such thing.
nitrogen
K is the chemical symbol of potassium.
Each metal has a specific chemical symbol.
Be is the chemical symbol for beryllium.
Iodine
zinc oxide
As is the chemical symbol of arsenic.