Iodine - 113, means iodine with mass number 113
To specify a particular isotope, add superscript and subscript on the left of symbol.
The superscript indicates the mass number (number of protons + neutrons)
The subscript indicates the atomic number (number of protons)
The iodine - 113 is writen
113
I [this the letter i]
53
superscript 113 on the left ofd the symbol is the mass number = protons + neutrons
I is the symbol (letter i)
subscript 53 on the left of the symbol is the atomic number (number of protons)
