One of my students wrote this in our Writing Feedback session - is it ok?
Unfortunately, the 'ampersand' (&) is considered an abbreviation, so I wouldn't recommend it for formal writing - just use 'and'.
Similar 'short' versions (abbreviations) to avoid:
ACRONYMS like the WHO (World Health Organisation) are acceptable, but use the name in full on its first use, no matter how well known the acronym is.
In the first mention, write "the World Health Organisation (WHO)" and then use "the WHO" for the rest of the essay.
Can you think of any other examples of abbreviations that you should avoid?