does the charge cloud get bigger as number of electrons increase? A level
In all cases, yes. Since the e- repel each other, so more e- means more repulsion which pushes them further apart.
Take the simplest example: a H atom - 1 p+ and 1 e- Give it a second e-, you now have 1 p+ struggling to hold onto 2e-, which are trying to get away from each other.