# What are some common mistakes students make with isotope notation?

##### 1 Answer

Mar 5, 2017

#### Answer:

Writing mass and atomic numbers the wrong way round.

#### Explanation:

Isotopes are written as

I was guilty of this for a long time too, I'd write the mass on the bottom because it's larger so it made more sense.

Isotopes should always be written with the big number on top.