Skip to main content

About this free course

Become an OU student

Download this course

Share this free course

Addiction and neural ageing
Addiction and neural ageing

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.


An ion is formed when an atom or molecule either loses or gains one or more electrons, leaving it with a positive or negative charge, respectively.

» Glossary