How can water split light like a prism?

Question: How can water split light like a prism?
- Keywords:
  light,
  prism,
  water
Asked by anon-207621 to Silvia, Scott, Oliver, Natalie, Michelle, Lowri on 14 Mar 2019.
- Natalie Lamb answered on 14 Mar 2019:
  
  Light is “bent” during refraction by different amounts, which separates out the different colours, depending on the colour of the light.
  
  A glass prism produces a spectrum (a rainbow) but a glass rectangle would not because of the way the different shapes bend the light. So if, for instance, water was in a bottle, the shape of the bottle would not be suitable to produce a rainbow. But water droplets in clouds are very symmetrical so can produce a spectrum, like this:
  https://www.scienceabc.com/wp-content/uploads/2018/10/raindrop.webp
- Scott Graham answered on 15 Mar 2019:
  
  i believe this occurs due to the shape of the water droplet. as the light hits the water it is bent around a process called refraction, it is this refraction process which cause this. this can also be show by placing a straw in a glass of water if you look at it side on it can sometimes appear that the top half of the straw is slighlty further away from the bottom half (see attached link)

Question: How can water split light like a prism?