# What is the isotope symbol for oxygen-18?

##### 1 Answer

May 20, 2017

#""_8^(18) "O"#

Recall:

#""_Z^A X# where:

#Z# is the atomic number, i.e. the number ofprotons.#A# is the mass number, the number of protons plus neutrons.#X# is your chemical symbol.

We know that oxygen atom is

#Z = 8#

and the mass number is...

#A = Z + 10 = 18#

Therefore:

#=> color(blue)(""_8^(18) "O")#